Fish Food Ingredients Analysis

Note: The following was originally published on and was written by Kmuda. The site is no longer live and I didn't want the below information to be lost so I've posted it here.

There are many documents and web sites dedicated to analysis of Dog Foods, Cat Foods, Cattle Feed, and feeds for other live stock. However, when I decided to research the ingredients found in fish foods, I found an absence of information. This article is an attempt to at least partially fill that void for anyone else interested in learning about fish food ingredients.

As a disclaimer, I am not a scientist, a biologist, a chemist, or a dietitian. What I am is a hobbyist, an aquarium enthusiast with almost 30 years experience with the goal of allowing the fish in my care to live out their life expectancy free of aggression, disease, and environmental or dietary induced ailments. I don't want to be responsible for feeding my fish anything determined by the government as “safe” even though it is banned for human consumption and otherwise labeled by scientific research as even “mildly toxic”.

Nor am I a fanatic. I understand. They are fish. I am not about banning foods because of their ingredients. I can, however, hope for better. If someone wants to feed a lower quality product, let them. But I want the option to feed a quality product absent toxic, potentially toxic, or even controversial ingredients. A food that contains natural proteins derived from appropriate aquatic animals and plants as opposed to something originating from a test tube, containing “by-products” with questionable digestibility, or proteins and starches not suitable for a fish's digestion.

With my dogs, I have been able to find holistic foods that answer these questions; that do not contain controversial ingredients. Not so with fish foods. The issue with fish food is they are lower on the list of priorities in the Pet Food industry, primarily because the consuming public is either ignorant or allowing of the inclusion of substandard ingredients. After all, they are just fish. In addition, not many of us maintain our aquariums well enough for our fish to live long enough for the chemicals added to their food to become an issue. An Oscar should live 10 – 20 years. Yet I'm not aware of a single Oscar that has achieved their expected life span. Why? Usually, the answer to that question will go back to environment, insufficient water changes. My fish will not suffer that issue. It's eliminated as a potential influence on negative health. That leaves food as the potential problem and the search for a food that does not present health risks while containing appropriate protein sources.

So began the research that has resulted in this article. Just what are fish food manufactures adding to our fish's food? Beyond that, are ingredient lists an accurate representation of the foods contents and what information do I need to select a quality food?

Beware of Proteins

Proteins are what we are looking for, right? A food with a protein count of 50% is good, right? Maybe not.

Not all proteins are created equal. It's less about protein content, it's all about the protein source. It was the search for proteins that resulted in all of the pet deaths a few years ago from melamine poisoning. Melamine had been added to meal products to boost protein levels. Let this be a lessen for you. The pet food industry pumps in proteins from wherever they can find them at the lowest cost possible, regardless of if these proteins can be properly digested by your fish. If their test tube reads 50% protein in the final product, they are happy. It does not matter if 30% of those proteins pass through your fish without being digested. Many of these non-preferred proteins have stacks of scientific paper behind them identifying how well they pack weight on salmon, tilapia, or other type of commercial fish. What they don't cover is how well they support a fish's lifespan. If you feed a toddler McDonald's cheeseburgers every day, I'm sure he'll pack on plenty of weight but it's unlikely to be conducive to long life.

A fish pellet manufactured with poor quality fish meal can be supplemented with high protein grains and by-products resulting in a high protein content listed on the ingredient label. So you look for those high protein content grains and by-products as a potential warning that a low quality meal was used. Brewers Dried Yeast (45% protein), Distillers Dried Grains with Solubles (30%), Soy Flour (60%), Wheat Germ (30%) and Soybean Isolate (95%) are some of the most common. An ingredient label with either of these products as one of the fist two or three ingredients is suspect.

Something else to consider, all proteins added to a tank via the introduction of food eventually re-manifest as nitrate. If the fish is unable to properly digest the proteins in the food, once passed through the fish, bacteria will. The only winners here are the fish food manufacturer, by taking your money for feeding the bacteria in your tank, and the water company, because you'll still be doing water changes to combat the nitrates resulting from feeding the bacteria. But you and your fish are no better off.

At their base, that is what this article and all of the individual analysis of specific fish food products you will find on this site are about, searching for and identifying the right proteins. Proteins which are preferred over proteins that are not.

What we are looking for are aquatic meat proteins and plant proteins that originate from something other than wheat, corn, or soy products. We are looking for natural proteins that do not originate in a test tube or as a by-product. To do this, you first have to understand how to read an ingredient list.

Understanding Fish Food Ingredients Lists

In order to evaluate an ingredient list you must first understand how pet food manufactures are allowed to manipulate them.

Wet Weight vs Dry Weight

By law, pet food manufactures are required to list ingredients in order of their weight, meaning the first item listed in the ingredient list should be the largest portion of the product. The second listed ingredient, the second. Etc… But laws do not require the ingredients to be listed in order by their weight in the final product. It only requires them to be listed by their weight as they were introduced into the manufacturing process. This allows pet food manufactures to manipulate an ingredient list via the ordering of ingredients at their wet weight. As an example, a food manufacturer may list “Whole Salmon” as the primary ingredient. However, once dried, as it must be to create a fish flake or pellet, the product will weigh 80% less than it was as a wet product. End result, it may have been the heaviest ingredient going into the manufacturing process but in the final product its weight is substantially less. Almost certainly not the #1 ingredient content of the food yet it is listed in the ingredient ordering that way.

In addition, whenever the word “Whole”, such as Whole Salmon, or “Frozen”, such as Frozen Krill, is used, absent the word “meal”, the initial weight during product manufacturing (as reflected in the final product ingredient list) may also have included the ice the product was packed in.

Product Splitting:

Another way companies manipulate ingredient list ordering is via a mechanism known as “product splitting”. Product splitting involves taking a single product, such as Wheat, and breaking it down into several different components, such as Ground Wheat, Wheat Mill Run, Wheat flour, Wheat Gluten, and (worse yet) Wheat Middling, with each of the “different” wheat products listed individually. As individual components, their weight may be less than the “Fish Meal” (or other preferred ingredient). Combined, they may very well be the primary ingredient in the food. If “Whole Wheat” is listed, absent other wheat products, then the order of “Whole Wheat” in the ingredient list can be considered accurate. Wheat flour + Wheat Germ  + Wheat Gluten + Wheat Middling, each listed individually, is down playing the totality of wheat as an ingredient, falsifying its order in the ingredient list.

Combine product splitting with wet weight vs dry weight and that “Whole Salmon” is almost certainly not the primary ingredient. It will be wheat and salmon may actually be a minor ingredient.

Wheat, Corn, and Soy products are commonly “split” ingredients. In the fish food industry, Wheat and Soy is used much more often than corn.

What do I look for in a Fish Food Ingredients List?

Aquatic Meat Proteins

The preference for a primary ingredient is a named meal protein, preferably a whole “named fish” meal such as Whole Herring Meal or “Whole Krill Meal”. Generic fish meals, for the most part, present their own concerns, as detailed a bit later. Use of “Whole Herring Meal” (or other whole named fish meal) indicates two things. First, the use of a meal product as the primary ingredient indicates its weight order, as reflected in the ingredient list, is accurate (listed at its dry weight). Second, use of the word “Whole” suggests the whole fish was used, not just the skin, scales, bones, blood, and other leftovers deemed unsuitable for human consumption, as may be the case with a generic “fish meal”, although some fish meals are comprised of whole fish. Use of the word “Whole” may also indicate something completely different. The difference between “Whole Herring Meal” and “Herring Meal” does not involve if the “whole animal” is used. With herring, the whole animal is always used because of the size of the fish It involves whether or not the condensed fish solubles, which are basically the evaporated stickwater, are returned to the meal prior to drying. “Whole Herring Meal” has this condensed stickwater added back, “Herring Meal” does not.

“Stickwater” results from the liquids pressed out of the cooked material. This liquid is run through a centrifuge to remove the oil for other uses. What is left behind is the “stickwater”, and contains about 20% of the total solids of the fish. Liquid is then allowed to evaporate, leaving behind “condensed fish solubles”, which you'll sometimes find as a separate ingredient on labels. Some products such as the API Foods, use this as their primary ingredient.

When these “condensed fish solubles” are added back to the meal, it becomes “Whole Meal”, or in the case of Herring, “Whole Herring Meal”. If these condensed fish solubles are not added back to the meal, the meal is simply identified as a meal, or in the case of Herring, “Herring Meal”.

So, what does this mean? Not only do we have to concern ourselves with use of the whole animal entering the manufacturing process instead of processing leftovers, now we have to be concerned about the meal product having these “condensed fish solubles” added back. It also means that from reading an ingredient label, there is no way to tell if the whole animal is used or not, unless they clarify it somehow, but “Whole Salmon Meal” may NOT an indication the whole salmon is used. It's may just be an indication that the condensed stickwater is added back to the meal before drying but the raw product entering the manufacture of the meal were actually processing leftovers and not the whole animal.

The industry has almost made it impossible for a normal human to diagnose what is included in pet food by reading an ingredient label.

There is an order of preference as it relates to meat proteins. Krill and Krill meal are the high end of optimum ingredients, following by Whole Herring Meal, followed by most other types of “Whole Fish Meal”, with acceptable fish being Salmon, Manhaden, Anchovies, Sardines, etc…, followed by meals in the same order that do not include the word “Whole”. Last in preference would be generic fish meal from unknown sources (names of the types of fish are not included).

Plant Proteins

Even carnivores in captivity need plant products in their diet. In the wild, they receive plant nutrition via the gut contents of their prey. In captivity, their prepared foods should compensate for this. At least consider Spirulina listed as a major ingredient a significant bonus. I consider it criteria. Spirulina is digestible and healthy for even the most hardcore carnivore.

Plant products are a natural source of many vitamins and minerals so their inclusion, in sufficient quantities, negates a need for massive supplementation with synthetic vitamins, which are less usable by the fish and sometimes even dangerous.

The same rules applying to meat proteins also apply to plant proteins. When attempting to identify a food for herbivores, the first ingredient should be a plant product in a meal form, such as “Spirulina Meal” or “Kelp Meal”. If the first ingredient is “Fish Meal” and then Spirulina or Kelp is listed later in the list as the third, fourth, or later ingredient, then the actual acceptable vegetable content of the food is very low. The food is just a standard fish food marketed as an herbivore/algae flake/pellet/wafer. Preferred plant proteins are actually a minor ingredient.

You also have to be aware of the same “wet vs. dry” concerns. An ingredient of “Kelp” or “Spinach” may be listed at their wet weight while “Dried Kelp”, “Dried Spinach”, or “Kelp meal” and “Spinach Meal” will be listed at their dry weight. Spirulina is only available as a dry product so regardless of how it is listed (spirunlina, dried spirulina, or spirulina meal) it's listing in the ingredient list should be accurate.

Multiple Protein Sources

In addition, you don't want a single form of acceptable protein. A quality food will list several forms of animal and plant proteins within the first line of ingredients. A significant majority of protein should come from named aquatic animals (fish, salmon, herring, krill, brine shrimp, plankton, squid) and plants (Spirulina, Kelp, Spinach, Algae, Vegetable Extract) and not from protein add-ons and fillers such as soy, wheat, and corn products, which should (ideally) be limited to no more than 20% of the food, although for herbivores and omnivores (such as Oscars) this can likely be increased to as much as 30%.

Vitamin Supplementation

Any quality food will contain all necessary vitamins and minerals. Look for sources of vitamin C, A, E, and B-complex. Quality natural ingredients, such as Spirulina, Kelp, Spinach, and vegetable extract will provide many of these vitamins naturally.

Warning: What You Don't Want To See in Fish Food Ingredients


Ethoxyquin is a fat preservative commonly found in pet foods. U.S. Coast Guard regulations specify that any fish meals transported by boat must be preserved with either BHA, BHT, Ethoxyquin, or a “tocopherol-based liquid antioxidant” (primarily to prevent fires aboard ship; unpreserved fish meals have been known to spontaneously combust). Because of cost and it is the most effective preservative, Ethoxyquin is the product used almost exclusively. While it prevents fish meals from becoming rancid, it has also been linked to several pet ailments, albeit not always scientifically, to include cancer, liver failure, and birth defects (amongst others). The “maximum allowable residue of Ethoxyquin in eggs, meat, poultry, apples, pears, poultry fat and livers for HUMAN use is 0.5ppm. In ANIMAL feeds, the maximum allowable concentration of Ethoxyquin is 150ppm.”

Despite USDA suggestions that Ethoxyquin is safe (actually, they say the unhealthy affects are “dose dependent”), I would not consider it something you want to find in your fish food. A 2005 assessment by the EPA determined that “studies indicate that Ethoxyquin is toxic to aquatic invertebrates, and mildly toxic to fish” when ingested. I feed my fish (and other pets) in the hopes of keeping them healthy. I don't want to be the cause of them ingesting anything even “mildly toxic”.

Use of Ethoxyquin is not restricted to fish foods. It is commonly found in dog and cat foods, less commonly today than several years ago. Dog and Cat owners rebelled against the industry, demanding the elimination of Ethoxyquin and have been largely successful, at least in the quality brands. The biggest difference, when it comes to our gilled friends, is that the predominant use of ethoxyquin is with “Fish Meal” and fish meal is the primary ingredient in most of our foods while it is usually found as a minor ingredient in most dog and cat foods. This means our fish are getting a “higher dose” and are therefore more likely to suffer the unhealthy affects. That and few of us care enough about the long term health of our fish to understand the dangers Ethoxyquin potentially presents. So as a hobby, we have largely been allowing.

The only applicable study that exists related to fish is a study conducted on tilapia. Based upon that study, the physiological affects of ethoxyquin are detected (in at least one species of fish) at the maximum allowable concentration of 150ppm, resulting in non chronic immunosuppression and pyknosis in the liver. We have no reason not to believe those effects will increase with duration, based upon additional studies that document ethoxyquin accumulation in fats and the liver, although such an assumption is admitedly conjecture as no long term study has ever applied to fish (or likely ever will). The only long term study ever conducted, period, was the original 1950s/1960s study by Monsanto where they studied a group of dogs for 5 years and found no problems, although the subsequent 1990s study commissioned by the FDA discovered potential issues in dogs at lower concentrations and shorter duration than utilized in the Monsanto study.

There are no studies related to fish that identify the Lowest Observed Effect Level (LOEL).

We know that the LOEL for dogs is 100ppm. Based upon information from the National Toxilogical Program Executive Summary of Safety and Toxicity Information with the target organs being, again (as in the fish study) the liver and kidneys, including increased liver and kidney weight.

We know that the maximum allowable concentration of ethoxyquin that can exist in our fish food is 150ppm. The FDA request to pet food manufacturers to voluntarily reduce the amount of ethoxyquin to 75ppm only applied to dog foods. But we don't know how much ethoxyquin actually exists in any of our fish foods, despite asking the various vendors for that answer. For some reason, dog food companies can provide this information and fish food companies cannot (the “holistic” dog food I feed my dogs contains 5ppm ethoxyquin. 5ppm falls within the “trace” designation.)

The only information I can find was a European study (sorry, lost the link) were various animal feeds were tested (not fish food) and they found an average concentration of 120ppm, although the FDA claims almost all dog foods already contained less than 75ppm before the requested reduction. I was able to identify that IAMs Dog Food contained 85ppm before the voluntary reduction and “Natural Life” contained 25ppm.

We also know that the human acceptable levels are far below any of this. 50x lower than what is accepted in fish food and 25x lower than what is accepted in dog food.

Aquarium fish, and fish in general, have been completely ignored as it relates to this area. Substantial research has been conducted in dogs, rats, and some research with livestock, although the research with livestock is more focused on determing the flow of ethoxyquin up the food chain to us. Like livestock, research has been conducted into ethoxyquin accumulation in the fats of farmed fish (a protection against human consumption of ethoxyquin) but these studies were not concerned with the health affects on the fish. But aside from the one study already quoted, no study exists on the effects of ethoxyquin on our fish.

We don't know if fish are more susceptible or less susceptable to Ethoxyquin than dogs. Based upon the one study that has occurred on fish, we can assume they are more susceptable than other animals studied as these effects were not detected in these animals at the same concentration, which would place fish's sensitivity closer to dogs. I can find no study of ethoxyquin as it relates to cats.

Most available information on Ethoxyquin comes from studies conducted in the 1950s and 1960s by the manufacturer (Monsanto), except for the revisit in the 90s, which focused on dogs and resulted in the requested reduced concentration in dog foods to 75ppm. None of the Monsanto or FDA studies involved fish.

So the question is very basic. Do you take the information that exists (and the absence of information) and apply a risk, which is my view, or do you take the information that exists (and the absence of information) and assume safety? Either way, it's an assumption as sufficient information simply does not exist to make an absolute affirmation either way. I consider the inability to make an absolute affirmation an unacceptable risk. Especially considering the experiences of dog owners and breeders, outside of the scientific analysis.

There are many mistruths associated with Ethoxyquin and product labeling. The law states that the ingredient list must contain Ethoxyquin if it is added to the food either directly or indirectly. This means that if the food manufacturer does not add Ethoxyquin directly but it is a functional component of the meal products used, then the label must state the existence of Ethoxyquin. However, based upon “Reminders” being sent out by the FDA, it would appear that many pet food manufacturers may be ignoring this rule. How this can be is a mystery. Any imported fish meals require specific labeling that includes the preservatives used and their concentration, otherwise it is not even allowed in the country. So fish food manufacturers, when they purchase the meal, have the information right in front of them. So they cannot claim it is “hidden”. The truth of the matter, based upon numerous communications I've had with various fish food companies, is they claim they don't have to list ethoxyquin if it's not directly added to the food by them. That is not how I interpret the law, but clarification will be achieved.

Since we don't know how much Ethoxyquin is used in any given fish food, concerns with its use at the maximum allowable concentration, and an absence of information detailing the effects of ethoxyquin on fish at any given concentration, I consider Ethoxyquin an ingredient to avoid.

There are alternatives to Ethoxyquin, even natural alternatives, even for imported fish meals. Despite mistruths spread primary by the industry itself, the law does not state that Ethoxyquin is the only preservative allowed to be used. Also listed as allowed is a “tocopherol-based liquid antioxidant”. Tocopherol would be perfectly acceptable. However, it would not be fair, when mentioning safe alternatives to ethoxyquin, to not clarify that there is a give and take. To achieve the added health safety of using mixed tocopherol's, you sacrifice shelf life and by sacrificing shelf life you increase the potential of feeding an oxidized and therefore toxic product. There is no argument that ethoxyquin is a more effective antioxidant. But it's no different than checking the expiration date on the bread before purchase or checking the expiration date on the milk before drinking it.

For every food we review in our Product Reviews section, we attempt to identify the existence or absence of Ethoxyquin.

UPDATE: Some additional information is available via a study conducted in April 2014 on Japanese Seabass that indicates Ethoxyquin concentrations above 13.78ppm have a negative impact on fish growth. The same study also identified that food containing less than 13.78ppm Ethoxyquin also had a negative impact on fish growth, an easily explained phenomenon resulting from the degradation of unpreserved fats. Regardless, for there to be a negative impact in concentrations above 15ppm highly suggests a yet to be defined (undiscovered) physiological interaction.

BHT (butylated hydroxytoluene)

A chemical antioxidant (preservative) designed to extend the shelf life and reduce fat spoilage (rancidity) of pet foods and pet treats. A known carcinogen banned in Japan, Romania, Sweden and Australia. It is known to stimulate adverse effects on liver and kidney function. BHT it is one of the “approved” preservatives allowed for use with imported meals.

Artificial Coloring Agents

Fish food manufacturers have a valid excuse for using controversial preservatives. There is no excuse for using artificial coloring agents, many of which possess known health risks and/or are carcinogens.

Your fish do not care about the color of the flakes and/or pellets you are feeding them. The pet industry adds artificial colors for marketing, to make the flakes and/or pellets appear more appetizing to us or to keep the color of the food consistent between production runs. The uninformed consumer thinks those green flakes are green because their content is primarily plant based. Chances are that's not the case. The green comes from a mix of Yellow 5 Lake and Blue 2 Lake. The flake is nothing more than bad fish meal, added non-preferred proteins, and chemicals. I use the existence of artificial coloring agents as an indication of the quality of the meals in their foods. Chances are, any fish food manufacturer using these agents will not be using quality fish meals.

So, to make the food more appealing to our eyes the industry adds chemicals that are banned in many countries. Avoid any foods that list any of the artificial coloring agents or use the phrase “natural and artificial colors” in the ingredient list.

Details associated with artificial coloring agents known to be used in fish foods are included in the “Ingredient Details” section of this article.

Synthetic Vitamin K (K3).

I'll list this under the heading of things you don't want to see but it's almost unavoidable. If you are going to feed a flake or pellet food, you almost certainly will find this listed as an ingredient. Synthetic Vitamin K (K3) will be listed in the ingredient list as one of the following:

Menadione Sodium Bisulfite
Menadione sodium bisulfate
Menadione sodium bisulfite
Menadione dimethylprimidinol sulfate
Menadione dimethylprimidinol sulfite
Menadione dimethylprimidinol bisulfite
Dimethylprimidinol sulfate
Dimethylprimidinol sulfite
Dimethylprimidinol bisulfate
Vitamin K supplement
Source of Vitamin K Activity

Menadione, also known as vitamin K3, is a synthetic version of vitamin K. The natural occuring compounds are vitamin K1 (Phylloquinone, from plant sources) and Vitamin K2 (Menaquinone, synthesized by bacteria in the digestive tract and absorbed by the body). Technically menadione isn't even a vitamin, but a precursor that is converted in the body after ingestion. Natural vitamin K is fat soluble, while menadione derivatives (pure menadione can not be processed) are water soluble and bypass the natural pathway of utilization by the body.

A peer reviewed article published by the Linus Pauling Institiute at Oregon State University states. “Although allergic reaction is possible, there is no known toxicity associated with high doses of the phylloquinone (vitamin K1) or menaquinone (vitamin K2) forms of vitamin K. The same is not true for synthetic menadione (vitamin K3) and its derivatives. Menadione can interfere with the function of glutathione, one of the body’s natural antioxidants, resulting in oxidative damage to cell membranes. Menadione given by injection has induced liver toxicity, jaundice, and hemolytic anemia (due to the rupture of red blood cells) in infants; therefore, menadione is no longer used for treatment of vitamin K deficiency. No tolerable upper level of intake has been established for vitamin K.”

Synthetic Vitamin K (K3) has been banned from over the counter human vitamin supplements.

Much like ethoxyquin concerns in the United States over the last decade, German pet owners have been in an uproar over Menadione Sodium Bisulfite. Studies conducted in Germany have identified the following concerns with Vitamin K3 and it's use in animal feeds.

  • causes cytotoxicity in liver cells
  • causes formation of radicals from enzymes of leucocytes, with the consequence of cytotoxic reactions
  • considerably weakens the immune system
  • possible mutagenic effects
  • damages the natural vitamin K cycle
  • has no effect on coumarin derivatives, which are often present in commercial food due to mold contamination (toxic when ingested)
  • causes hemolytic anemia and hyperbilirubinemia, not just linked to large doses
  • disturbs the level of calcium ions (Ca2+) in the body, which is an important factor fibrinolysis
  • is directly toxic in high doses (vomiting, albuminuria), unlike natural vitamin K
  • builds up in tissue and has been detected in eggs, meat and milk of animals supplemented with menadione derivatives
  • causes irritation of skin and mucous membranes
  • causes allergic reactions and eczema

Studies performed specifically on fish (Salmon) identified increased mortality rates when compared to fish receiving natural vitamin K. Other studies identify it causes problems with the liver and kidneys. Despite these studies and despite readily available natural alternatives (kelp, spinach, and virtually any green leafy vegetable), the industry, as a whole, is utilizing the synthetic version of vitamin K (K3). Some fish food manufactures even add Menadione Sodium Bisulfite (MSB) when their food already contains one of these natural sources.

While not verified, the only AAFCO approved Vitamin K supplement for adding to animal feed appears to be Vitamin K3 (Synthetic Vitamin K).


Methionine is an essential amino acid that aids the liver in processing fats. Naturally found in meat products, subsequent supplementation of fish food with DL-Methionine (as indicated by existence of DL-Methionine in an ingredient list) is a potential indication the food is low in meat protein.

This is not a hazardous or toxic compound. I only use it as an indicator. Provided the fish food has sufficient meat protein content there is no need to supplement with Methionine. So its existence in the ingredient list is a potential indication that a low quality fish meal is used and a majority of proteins are coming from plants or grains. This is not a universal truth. Some quality foods supplement with DL-Methionine and it would be an almost required supplement in a true herbivore food, but my experience is that its use is more common in low quality foods. So the appearance of this supplement gives cause for skepticism and closer analysis of the ingredients.

Meat Meal

At a minimum, Meat Meal contains parts of animals (mammals) considered inedible as well as diseased and dying animals unsuitable for human consumption. Even more outrageous, it may contain anything from zoo animals, to road kill, to fetuses, to potentially even euthanized dogs and cats (hidden in the legal paper work as “condemned animals”). No pet food should contain these ingredients, let alone a fish food that should contain aquatic animal protein, not mammals and poultry.

Poultry Meal

Poultry meal is a dried product manufactured from the leftovers of processed poultry after all of the best parts are used for other purposes. It can be expected to contain some amount of feathers. Digestibility is questionable.

Fish foods should contain aquatic animal proteins, not mammals and poultry.

Bottom Feeder Foods

My analysis of fish food ingredients finds the lowest quality and most egregious ingredients in foods labeled for “bottom feeders”. As a result, pay close attention to the ingredient list for any of these foods. Only in bottom feeder foods did I find ingredients such as “Meat Meal”, “Poultry Meal” and even “hydrolyzed feathers”.

As a general statement, Bottom Feeder Foods contained lower levels of preferred proteins and higher levels of non-preferred proteins (such as wheat, soy, and corn) than other types of fish food.

Fish Food Ingredients Details

Preferred Protein Sources

Preferred protein sources are those products we would prefer to comprise a majority of the food. The goal is for primary protein sources to originate from aquatic animal or aquatic plant proteins, not from binders and less digestible protein sources (covered later as “Non-Preferred protein sources”.)

Fish Meal:

Fish Meal is a very generic term that can indicate anything from a quality to a far inferior product. As a general statement, you would prefer to see an ingredient such as “Whole Salmon Meal”, which would indicate the inclusion of the entire fish. Absent this, the generic term of “Fish Meal” potentially identifies a dried product primarily manufactured from the leftovers of processed fish after all of the best parts are used for other purposes. Some fish meals are comprised only of bones, scales, skin, blood, and internal organs deemed unsuitable for human consumption.

The above statement requires a little clarity. In the manual that governs (suggests) pet food ingredient labels, the AAFCO defintion of fish meal is “the clean, dried, ground tissue of undecomposed whole fish or fish cuttings, either or both, with or without the extraction of part of the oil.” There is no AAFCO definition for “Whole Fish Meal”, such as “Whole Salmon Meal”, so any fish food company that utilizes “Whole Salmon Meal” as an ingredient on their ingredient label is technically out of compliance with AAFCO guidelines. However, AAFCO has not left any mechanism in their guidelines allowing the consuming public to evaluate product quality as, according to their “allowed” definition, “Fish Meal” comprised of 12 month old scales, skins, bones, blood vessels, and fins would recieve the same name on an ingredient label as would fresh whole salmon compiled into a meal. What this means to us, when trying to evaluate an ingredient list, is that an ingredient of “Salmon Meal” may or may not consist of the “Whole Salmon”. An ingredient of “Fish Meal” may or may not consist of the “Whole Fish”. In essence, there are no properly defined standards by which a determination of quality can be made. So (at least) some fish food manufacturers are filling the void by labeling outside of the defined standard, listing an ingredient such as “Whole Salmon Meal”. Since there are some truth in ingredient label laws, if “Whole Salmon” is listed then “whole salmon” must be there, so this can be assumed by us, as the consuming public, to be a superior product over “Fish Meal”. If one company does this and gains a market advantage, then everyone does it or looses. So those foods who continue to label as “fish meal” or “salmon meal” are doing so because the “truth in ingredient” laws that do exist prevent them from identifying it as “whole salmon” or “whole fish”, because they are using scraps, not the whole fish. This is the approach I when evaluating ingredients of the indivual food product reviews.

Use of the generic term of “Fish Meal” indicates the species origin of the fish included in the meal is a conglomerate of different types of fish. Some more desired than others. Some potentially not desired.

It is virtually impossible to determine if the fish meal included in your selected food is a quality meal or an inferior product. Some fish meals may be several months to possibly years old before being included in your fish's food and some meals will contain higher quality base ingredients than others. Fresher meals will contain higher levels of nutrients than older fish meals. Fish meal produced from materials that have been allowed to degrade prior to being processed can contain high levels of histamines and can be toxic when consumed over a long period of time. Reputation of the company producing the foods is all you have. Of the research I've conducted, the only generic fish meal for which I have a level of comfort are those fish meals included in Hikari products. Hikari manages product quality from the beginning to end of the process. This is not to say that other companies do not. They very well may, but they are much less forthcoming with information involving the process.

Any fish meals transported by boat are required, by law, to be preserved. Almost exclusively, Ethoxyquin is the preservative utilized. The same code of regulations that governs use of preservatives also identifies that fish meal older than 12 months cannot be imported, yet that is nothing more than a piece of paper attached to the product identifying its age. Are we to have faith that the same industry that placed melamine into meal products to boost protein content is above placing an inaccurate date on a piece of paper?

Knowing the country of orgin for any specific fish meal provides an indication of the type of fish utilized in the meal. Fish meal is manufactured primarily from anchovies in Peru; menhaden in the United States; pout in Norway; capelin, sand eel and mackerel in other parts of northern Europe; and sauries, mackerels and sardines in Japan.

Knowing the country of origin for fish meals also provides an indication of the amount of Ethoxyquin utilized to preserve the meals. Fish Meals originating from South America are known to contain very high levels of Ethoxyquin. Records exist showing ethoxyquin concentrations of between 400ppm and 1000ppm are not uncommon.

Herring or Salmon Meal (or any other type of “named fish” meal):

Not to be confused with “Whole Salmon Meal” (or other whole fish meal). This is a meal produced from the leftovers (the components deemed unusable for human consumption) of processed salmon (or other named fish). The primary difference between this product and generic fish meal is we know specifically which species of fish the meal is comprised of. Salmon Meal, specifically, contains higher levels of beneficial oils than many other fish used in generic fish meals. Salmon skin is also high in astaxanthin, a color enhancing carotenoid and powerful antioxidant discussed later in this article.

Studies conducted by the University of Albany’s Institute for Health and the Environment have identified significant contaminant levels in farmed salmon. “In particular, four substances that have been well studied for their ability to cause cancer-PCBs, dioxins, dieldrin, and toxaphene-were consistently and significantly more concentrated in farmed salmon.” Contamination is significant enough that the human recommendation for the consumption of farmed salmon is reduced to a “one-half to one meal per month-based on U.S. Environmental Protection Agency (EPA) consumption advisories for these contaminants. A meal was considered to be an eight-ounce portion.”

It can be safely assumed that a large majority of the Salmon Meal found in fish foods originate from farmed salmon. Prepared dried foods fed to farmed salmon are the suspected cause. Further human recommendations are to remove the skin and fats prior to cooking as this is where a majority of the contaminants will be stored. These same skin and fats that are recommended for removal will be a primary component of Salmon Meal.

As a general statement, you would prefer to see a “named fish” meal over generic fish meal in an ingredient list. However, a “whole fish” meal would be preferred over a “named fish” meal.

Other concerns as associated with “Fish Meal” apply, including use of Ethoxyquin as a preservative.

Whole Herring or Whole Salmon Meal  (or any other type of Whole “Fish” Meal):

A dried product manufactured from the entirety of the fish. A higher quality product than generic “fish meal” as it contains the actual meat and flesh of the fish. Not just the skin, scales, bones, blood, and other leftovers. Whole Salmon Meal is a preferred ingredient due to its high content of omega 3 and omega 6 fatty acids. Salmon skin is a good source of Astaxanthin. Herring would be preferred over Salmon because of higher Omega 3 and 6 levels and lower concerns of toxin contamination.

Other concerns as associated with “Fish Meal” apply, including use of Ethoxyquin as a preservative. Contaminant concerns as exist with “Salmon Meal” also exist with Whole Salmon Meal.

Whole Salmon (or any other type of Whole “Fish”)

When you pull a pellet out of the bag, does it look like a “Whole Fish”?

Marketed as “preferred” over meal products but this is marketing. I would prefer to see a whole fish meal product listed as a primary ingredient.

The product must be dried before it can be turned into a pellet and the dried product is actually a “meal”. So what winds up in the food is actually “Whole Salmon Meal”. The problem is that ingredients are listed by order of weight. The act of drying the product results in it weighing about 80% less than the wet product, yet its weight value (as it applies to ingredient order) will be the wet weight. In addition, you must be aware that the weight value may also include the weight of the ice the “whole fish” is packed in. So if “Whole Salmon” is listed as the primary ingredient and a binding agent (wheat product) is listed next, the ingredient list is not accurate (it's a bona-fide but legal lie). In reality, the meat product (Whole Salmon) should be much farther down the list.

Use of “Whole Salmon” (or any other type of Whole “Fish”) does provide a positive indicator. While a pellet can never be considered “fresh”, whole fish listed as an ingredient (as opposed to “whole fish meal”) is a better indicator the initial meat product utilized in the manufacture of the food is fresher than would be a meal product, thereby being higher in nutrients.

When evaluating any ingredient list beginning with Whole Salmon (or any other type of whole fish) the first several ingredients should be meat products (either another type of whole fish or a meal product), allowing for increased confidence that meat proteins are indeed the primary component of the food.

It is conceivable that a fish food manufacture could utilize enough “Whole Salmon” (or other whole fish) so that the ingredient ordering of the final product is accurate. However, doing so would require significantly more expense (requiring 80% more “whole fish”) for that product to remain the #1 ingredient, with the cost likely making the food too expensive to compete with other products being sold to either a public who does not care or does not know. In addition, you would think any company undergoing this expense would let us know. None have. It's not specified in any marketing and attempts to get clarification from companies using “Whole Fish” have thus far gone unanswered. Inevitably, the question of the actual ratio of “whole salmon” to binders and non-preferred proteins is met with silence, an indication the ratio is not what we want.

Use of “Whole Salmon” (or any other type of Whole “Fish”) does not eliminate concerns with use of Ethoxyquin as a preservative. Contaminant concerns as exist with “Salmon Meal” also exist with Whole Salmon.

Salmon Fillets

Exactly what it sounds like, fillets of Salmon. Instead of “Whole Salmon”, which would be the entirety of the fish, Salmon Fillets will be cuts of the salmon meat. This is considered a quality ingredient but one that comes with a warning. Like “Whole Salmon”, Salmon Fillets will be listed at their wet weight, artificially inflating their order in the ingredient list.

Spirulina Algae Meal

Spirulina is sometimes called “The Most Nutritious Food on the Planet”. Rich in raw protein and seven major vitamins: A1, B1, B2, B6, B12 (one of the best natural sources for B12, although the bioavailability of its B12 is in dispute by many researchers), C and E. It naturally contains beta-carotene, color enhancing pigments, and a whole range of minerals. In addition, Spirulina has 62% amino acid content and contains all essential fatty acids and eight amino acids required for complete nutrition. It is easily digested due to the fact that Spirulina cells do not have cellulose walls.

I consider spirulina the secret weapon in being successful in long term fish keeping. Look for a food that contains spirulina high in the ingredient list. Spirulina is only available in a dry form, so regardless of how it is listed on the ingredient label (spirulina meal, dried spirulina, or spirulina), it's ordering in the ingredient list should be accurate.

Krill Meal

Krill is a preferred ingredient in fish foods. Krill are small shrimp like crustaceans. While Krill may be found in all of the world's oceans, Antartic Krill is the ingredient we most desire.

Krill, especially Antartic Krill, is an excellent source of proteins, amino acids, omega 3 oils, and color enhancing carotenoids. Krill shells are perhaps the best natural source of astaxanthin, a color enhancing carotenoid and extremly powerful antioxidant.

Krill is only available in its meal (dry) form, so it's location in the ingredient list should be accurate. However, there is a potential diffence between “Krill Meal” and “Whole Krill Meal” as Krill tails are sometimes processed for other use.

Shrimp Meal

Shrimp meal can be made from either cull shrimp that are being processed before freezing or from whole shrimp that is not of suitable quality for human consumption. The material to be made into shrimp meal is dried (sun or using a dryer) and then ground. Shrimp meal has been used in trout and salmon diets as a source of pigments to impart the desirable color in the tissues. As a source of protein, shrimp meal is inferior to fish meal. As a source of color enhancing carotenoids, it is inferior to Krill meal.

Condensed Fish Protein Digest (aka hydrolized fish protein)

Consists of the condensed enzymatic digest of clean undecomposed whole fish or fish cuttings using the enzyme hydrolysis process. It can better be defined (and is listed on some labeles) as fish protein hydrolysate. The hydrolization process involves the liquification of whole fish or fish cuttings in a vat of enzymes. The bones and scales are discarded with the subsequent slurry passed through a spray dryer. The end product is a highly digestible protein that is practically void of ash and phosphate.

Euphasia pacifica plankton (or Plankton)

Basically a smaller version of krill, to which it is nutritionally comparable while providing the same benefits. If the non-geographical word “Plankton” is used, it will almost certainly not be plankton from the Antarctic Ocean. As with Krill, Plankton from the Antarctic ocean is preferred.

Euphasia superba plankton ocean.

Same as Euphasia pacifica plankton except from the Antarctic Ocean whereas Euphasia pacifica plankton will be from the Pacific ocean. Just as with Krill, plankton from the Antarctic region is preferred.

Sea Clams

Aka Atlantic Surf Clam. A quality ingredient however, absent the use of the word “meal” in the ingredient list, it will be ordered based upon its wet weight, potentially even including the weight of the shell, which will not be included in the food.

Earthworm Meal

A dried product manufactured from earthworms. Earthworm meal accelerates growth, develops muscles, puts on weight, covers protein and amino acid deficiency, improves sexual performance, and stimulates appetites. Earthworm meal is a quality supplemental ingredient for all fish or primary ingredient if using a food to condition breeders.

Algae Meal

A dried product manufactured from blue-green algae. While Spirulina Algae Meal would be preferred over standard Algae Meal, Algae Meal remains a quality ingredient containing amino acids, vitamins, and trace elements. It boost the immune system, increases energy levels, and improves general health. The Chlorophyll and phytochemical content results in an effective antioxidant to prevent cell damage and aid detoxification in the body.  Algae Meal is low in fat and high in fiber.

Kelp (and Kelp Meal)

Kelp is large seaweed in the brown algae family. A good source of iodine for thyroid function and chlorophyll. A good source of Dietary Fiber, Vitamin C, Pantothenic Acid, Zinc, Copper, Riboflavin, Folate, Calcium, Iron, Magnesium and Manganese.

Kelp is a very good natural source of Vitamin K. Fish foods should use Kelp instead of synthetic vitamin K.

Mussel Meal

A dried product manufactured from the edible meat, not the shells, of mussels. It is high in proteins and calcium.

Seaweed Meal (aka Dried Seaweed Meal)

See “Kelp” or4 “Ulva Seaweed”

Silkworm pupae meal

After the silkworm die the spent pupae are easily collected and can be used as a supplemental protein source. Large quantities of spent silkworm pupae are produced as a byproduct of the silk industry and it is commonly used in fish foods in Asian countries. The meal contains the exoskeleton and the contents of the body cavity. Chitin, which is a component of the exoskeleton, contains approximately 25 % of the protein content, which is not composed of amino acids and is not digestible.

Digestibility of the proteins in silkworm meal was found to be similar to fish meal.

Ulva Seaweed

Ulva Seaweed has been tested on fish in several scientific studies with positive results. It possesses pigments which contain strong anti-oxidants, contains 28% protein, which is comprised of all 9 essential amino acids including Lysine, is rich in magnesium, potassium and calcium, and contains essential vitamins: Vitamin A, B and C.• It is especially rich in Vitamin B-12


Non-Preferred Protein Sources and Binders

When judging protein content of fish foods it is necessary to perform some mental math (although you don't have all of the numbers.) Preferred proteins combined, should out weight all non-preferred proteins combined. So you must mentally calculate the totality of all of the ingredients listed below as non-preferred protein sources against the totality of the ingredients listed previously as Preferred Protein sources (keeping in mind wet weight vs. dry weight). Of course, anytime the generic term “Fish Meal” is utilized these calculations are further complicated because you have no way of knowing, aside from company reputation, the quality of the meal and its protein content. Nor we do we know the actual percentages of the individual ingredients.

When performing this mental math, what you'll find is that very few available foods actually add up. What we are feeding our fish are binders and non-preferred proteins.

Many of these “non-preferred” ingredients are very high in proteins. At issue is these proteins are largely derived from starches and carbohydrates. The ability of fish to digest these proteins is questionable. Not to mention high starch content brings into play an entirely new discussion of glucose, glycogen, and body weight. Suffice it to say that if you are feeding your fish a diet heavy in the below non-preferred protein sources you are likely making your fish fat, which includes adding fat to the liver. Fatty liver disease is a leading cause of death in captive fish.

Some content of these ingredients is expected, even necessary. But they really should not make up more than about 20% of the food, although for herbivores and true omnivores (such as Oscars) this can likely be increased to as much as 30%.

Brewer's Dried Yeast:

A by-product of the beer making process, this ingredient contains about 45% protein and is rich in Vitamin B. Its use in fish foods is as either as a protein source or a vitamin supplement. Studies do exist identifying its capacity to improve fish growth rates. When used as a supplement comprising between 2% and 4% of the food, this is an acceptable product. When used as a primary provider of protein comprising 25% or more of the food it is less acceptable as protein digestibility concerns have been documented.

Corn Gluten Meal

A by product of corn processing containing “medium levels” of protein. Also used as a herbicide. Corn Gluten is used in fish foods as a low cost alternative to increase the protein content of the food. Digestibility is questionable. Not a preferred ingredient.

Corn Starch

Cornstarch, also sometimes called corn flour, is produced by grinding, washing and drying the endosperm of the corn until it reaches a fine, powdery state. Corn starch is gluten free. Its use in fish foods is as a binding agent and filler. Digestibility is questionable.

De-hulled Soybean Meal

Dehulled Soybean meal is 48% protein. A product of Soybeans after they are cracked, dehulled, oil extracted and toasted. It is a high protein, low fiber product. A preferred “non-preferred” protein as it is higher in protein content than wheat products and lower in fats.

Distillers Dried Grains with Solubles

A by-product of the ethanol industry. The wet mash that is left over after distillation of the ethanol contains the remains of those grains, but the starch has been fermented so the leftover mash is actually low in starch. It is higher in protein than corn gluten meal although digestibility is questionable. The potential exists for it to contain fungal and mold toxins. Not a preferred ingredient.

Dried Bakery Product

A mixture of surplus and unsalable materials collected from bakeries and other food processors. In other words, old stale bread, cakes, tortillas, pasta, cookies, candy,.etc… It is added to fish food as a source of protein and a flavor enhancer (sure give the fish a donut).

Feeding Oatmeal

This is not “Oatmeal”  as in what you had for breakfast. This is “Oat MEAL”, as in leftovers after the oats are processed for what you had for breakfast. It is classified as “animal feed grade oat meal” obtained in the manufacture of rolled oat groats or rolled oats and consists of broken oat groats, oat groat chips, and floury portions of the oat groats, with only such quantity of finely ground oat hulls as is unavoidable in the usual process of commercial milling.  It must not contain more than 4 percent crude fiber. A grain product high in carbohydrates. Protein content is around 11%. Fat content is around 5%. It is added to fish foods as a filler/binder, an inexpensive source of protein, and probably because they think you'll think it is the same thing you had for breakfast.

Gluten Flour

Wheat flour that is treated so that wheat bran and starch are removed. This means it’s much lower in carbohydrates, and much higher in protein. A quarter cup (30g) of pure gluten flour can contain 23 grams of protein,

Ground Brown Rice

A quality grain added to fish foods as a protein source. Ground brown rice uses the whole grain, not just processing leftovers

Potato Protein

Potato Protein is derived from de-starched potato juice from which the “proteinaceous fraction has been precipitated by thermal coagulation followed by dehydration” (a fancy way of saying “potato juice”). Its use is wide spread in dog foods, even high end dog foods. Added as an inexpensive protein source.

Rice Bran

Rice bran is the layer between the inner white rice grain and the outer hull. While comprising just 8% of total weight, Rice Bran (which includes the germ) accounts for 60% of the nutrients found in each rice kernel. A good source of dietary fiber, Iron, Magnesium and Phosphorus. Oils contained within rice bran spoil easily.

Soy Flour

A preferred binding agent as it possesses increased nutritional benefits over wheat and corn fillers although it is not as effective a binder.

Soybean Isolate

A highly refined and purified form of soy protein. Soy isolate is 90% to 95% protein and nearly carbohydrate and fat free. Added to fish foods to increase protein content. Considered a quality ingredient but you don't want it as a primary protein source. It should never be listed higher in the ingredient order than are the meat proteins (keeping in mind wet weight vs dry weight of the meat proteins). One of the human uses for this product is in infant formulas.

Soybean Meal

A preferred filler and binding agent as it possesses increased nutritional benefits over wheat and corn fillers although it is not as effective a binder

Sunflower Meal

Sunflower meal is the by-product of the oil extraction process. Oil is the majority value of sunflower seed and the meal is considered a by-product. Commonly used in cattle feed. It's use in fish foods is more likely as a marketing ploy than any nutritional or binding purpose, although it should make a decent binder. But it's nutritional value is low.

Wheat Germ Meal

A good natural source of Vitamin E, Thiamine, Zinc and Iron. Preferred over Wheat Flour and can serve the same filler/binding function. Usually added to fish food to boost protein content although it could be better utilized as a natural source of vitamins and minerals.

Listed separately but in the same ingredient list as other Wheat products, is an example of product splitting.

Wheat Gluten Meal

Added to fish foods to boost protein content. Wheat gluten is derived by processing whole wheat. First it is cleaned to eliminate the flour and the bran. Next it is steeped to help release the germ. The wheat is then ground to completely release the germ from the gluten. Centrifugation separates the two portions. Further centrifugation separates the gluten and the starch portions. Drying the gluten portion yields wheat gluten in a powder form.

Listed separately but in the same ingredient list as other Wheat products, is an example of product splitting.

Wheat Flour

Wheat flour is a powder made from the grinding of wheat. Its use is as a binding agent to hold the pellet together. Use of binding agents are necessary but you don't want wheat as a primary ingredient.

Listed separately but in the same ingredient list as other Wheat products, is an example of product splitting.

Wheat Middlings

A by-product of the wheat industry. Basically floor sweepings. Used in fish foods as a filler. Not a preferred ingredient.

Listed separately but in the same ingredient list as other Wheat products, is an example of product splitting.

Supplements, Chemicals, and Lesser Ingredients

Alpha Starch

Used in fish foods as a binding agent. Originated in Thailand where it was used by eel farmers in the manufacturing of eel food. I am unable to find actual content or nutritional values of this product. But it appears to be a modified tapioca starch. Tapioca is gluten-free, almost completely protein-free, and contains practically no vitamins.

Aluminum Sulfate

A source of aluminum, a necessary dietary mineral.


A color enhancing carotenoid and powerful antioxidant. Can be obtained naturally from krill, krill shells, shrimp shells, and salmon skins. Specifically enhances red coloration. A preferred ingredient in Oscar foods and for other fish where enhanced red coloration is desirable.

Most often thought of in the aquarium community as a red color enhancer, Astaxnthin's primary benefit may be it's powerful antioxidant properties. It is referred to as the “King of Carotenoids” for this reason. Beyond it's healthful benefits, Astaxanthin may directly help counter the effects of long term exposure to nitrates.

Astaxanthin is a powerful anti-inflammatory. Studies indicate exposure to excessive nitrates results in higher bloods counts of monocytes, neutrophil, TLC, and creatine, while impacting antibody production, all indications of an inflammatory type infection affecting muscle tissue and internal organs. Astaxanthin's powerful anti-inflammatory properties can help elevate these issues. Astaxanthin is a carotenoid, related to beta-carotene, lutein, and canthaxanthin, but it has a unique structure, and works in some very unique ways. For example, most other antioxidants are depleted after they've transferred their free electrons. But Astaxanthin has a massive surplus, allowing it to remain “active” far longer — at least one order of magnitude more than most other antioxidants. It donates electrons to neutralize free radicals, and then rejects the excess energy primarily as heat. But the Astaxanthin remains intact — there are no chemical reactions to break it down, which is what occurs in most other antioxidants. Astaxanthin also acts on at least five different inflammation pathways, and maintains balance within the system.

  • Astaxanthin combats fatigue. It is believed that Astaxanthin provides the energy and endurance Salmon require to swim upstream. Nitrate has the opposite effect, educing fatigue.
  • Astaxanthin increases metabolism, which improves hunger, while inhibiting bodyweight gain. Nitrate has the opposite effect. A 60 day study conducted on mice identified a high-fat diet containing 30mg Astaxanthin resulted in 15% less body weight, 34% less adipose tissue, 58% less liver triglycerides, plasma triglycerides, liver weight, and total cholesterol, when compared against the control group. Pay particular attention to a reduction in liver weight. Fatty liver disease is a leading cause of death among large South American Cichlids.
  • Astaxanthin improves immune response, inhibits cancer cell growth, reduces bacterial load, and gastric inflammation. Studies have proven Astaxanthin supplements increases the activity of natural “killer cells”, without increasing the population of these cells (which would result in them attacking the body in a manner in which they should not, resulting in an inflammatory response, such as asthma). Astaxanthin also raised levels of T and B cells, key cells of the immune system. This indicates Astaxanthin stimulates infection and cancer fighting components of the immune system while suppressing immune responses that create needless inflammation. This directly counters the primary impacts of nitrate toxicity, which is destruction of the immune system.
  • Excessive Nitrate damages the red blood cells, impairing their ability to carry oxygen (anemia). Astaxanthin protects red blood cells from these effects. Human studies identified the significant of these improvements as “profound”.

Beta Carotene

Source of Vitamin A precursor, aids immune response.

BHT (butylated hydroxytoluene)

A chemical antioxidant (preservative) designed to extend the shelf life and reduce fat spoilage (rancidity) of pet foods and pet treats. A known carcinogen banned in Japan, Romania, Sweden and Australia. Stimulates adverse effects on liver and kidney functions.


A water soluble synthetic vitamin generally classified as a B-complex vitamin. Aids in the metabolism of fats and amino acids.

Blue 2 Lake

A synthetic chemical produced by the fusion of sodium phenylgycinate and indoxyl in a mixture of sodamide and caustic soda. Added to fish food as a coloring agent. Serves no nutritional benefit.  Known to cause hyperactivity, chromosomal damage, nausea, high blood pressure, vomiting, breathing problems, allergic reaction and skin rashes. This chemical has been found to cause brain cancer in rats. Blue 2 has been banned in Sweden, Switzerland, Norway, Germany, France, Belgium, Australia and the British Commonwealth.


A milk protein and source of calcium. A very common allergen and cause for lactose intolerance. There has never been a study to determine if fish can be lactose intolerant.

Calcium Montmorillonite Clay

Calcium montmorillonite clay is a recognized nutrient, detoxifying agent, and bactericidal. It contains 67 minerals, including calcium, iron, magnesium, potassium, manganese, and silica as well as trace elements, those appearing in very tiny amounts. While the mineral content, being extremely high, sets the stage for replenishing dietary deficiencies, the bioavailability of these minerals is debatable. Regardless, the primary benefit may be as a detoxyifying agent. The adsorption (and absorption) effect of this clay has been proven effective in the removal of mycotoxins, fungi, heavy metal, and other toxins from the intestinal tracks of animals. It is also proven as a bactericide, with protective effect against several pathogenic intestinal bacteria such as E. Coli.

Calcium Pantothenate

A source of vitamin B-5

Calcium Propionate

A preservative commonly found in bread and baked goods. Naturally found in butter and some types of cheese. Potentially toxic in vitamin deficient animals if consumed in doses much higher that is found in our fish foods. Rated by the “Pesticide Action Network North America” at the same level of toxicity as vitamin C.


Canthaxanthin is known mainly as the natural pigment of the orange-yellow Chanterelle mushroom, but also occurs in various lower animals, some crustaceans, insects, fishes and birds. Besides its pigmentation properties, Canthaxanthin has various physiological functions and can be converted into vitamin A in case of deficiency. Specifically enhances orangish/red coloration. A preferred ingredient in Oscar foods and for other fish where such enhanced coloration is desirable.

Chlorella Algae

Chlorella is a genus of single-cell green algae belonging to the phylum Chlorophyta. It contains Carotenoids like vitamin A (beta-carotene) and alpha-carotene, and lutein, Powerful antioxidant vitamins C, D, E, and even the elusive vitamin K. A higher concentration of chlorophyll than any other plant on planet earth, the super antioxidant alpha-lipoic acid , B-vitamins – thiamine (B1), riboflavin (B2), pyridoxine (B6), niacin, pantothenic acid, folic acid, vitamin B12, biotin, choline. It contains minerals including phosphorus, calcium, zinc, magnesium,and iron, and more protein per ounce than steak.


Vitamin D3

Choline Chloride

An organic compound added to animal feeds to accelerate growth. Also aids in preventing fatty liver disease.

Copper Sulfate

A source of copper. Aids in bone formation, iron absorption and protein metabolism. There is some controversy associated with copper sulfate but it only involves use of this product at high doses. There is so little of it in our fish food that it presents little concern. Also used in human supplements. However, you want to find this towards the bottom of the ingredient list.

Cobalt Sulfate

A source of vitamin B12. Also used to treat some forms of anemia (note: the first impact of nitrate on fish is anemia).


A source of vitamin B12. Also used to treat some forms of anemia (note: the first impact of nitrate on fish is anemia).

D-Activated Animal Sterol

An animal sterol treated with uv-radiation to form Vitamin D1. In essence, this is a synthetic product that simulates how animals autocreate vitamin D from sunlight. Its useful supplement for our fish that receive no sunlight.

Dehydrated Alfalfa Meal

Dehydrated Alfalfa Meal contains an abundance of vitamins, minerals, and nutrients, including saponins, sterols, carotene, phytoestrogens, flavonoids, alkaloids, acids, vitamins (including A, B-6, D, E, K, and U), amino acids, sugars, proteins, minerals (e.g., calcium, chlorine, copper, magnesium, iron, phosphorus, potassium, sodium, and sulphur), as well as trace elements.

Dicalcium Phosphate

A calcium supplement commonly found in breakfast cereals, although the available calcium is inorganic. It is added to fish food primarily as a binding agent to create a firmer pellet or wafer. It is derived from bones. Also contains phosophorous and other minerals. Can become toxic. Known to cause kidney stones and may contribute to soft tissue calcification.

DL alphatocophero (E)

Synthetic vitamin E


An essential amino acid. Methionine is natural found in meat products so the supplementation of a food product with DL-Methionine (as indicated by existence of DL-Methionine in an ingredient list) is an indication the food is low in meat protein. Unless you are reading an ingredient list of a vegetable based food for herbivores, this could be a potential indication of an inferior food.

Ethylenediamine Dihydroiodide

A source of iodine

Ferrous Chloride (aka Iron Chloride)

A source of iron.

Fish Protein Concentrate

Fish protein concentrate is any stable fish preparation, intended for human consumption, in which the protein is more concentrated than in the original fish. A better protein source than fish meal as it will not contain rancid fats, is manufactured under more hygienic conditions, and is manufactured from fresher ingredients.

Fish Solubles

A by-product of fish canning and fish oil industries. During the processing of fish to recover the oil fraction a mixture of water and oil is produced. Then after this mixture is centrifuged to remove the oil the water containing fraction can then be condensed or dried to produce condensed fish solubles or dried fish solubles. A source of protein but may not be well digested. Again, we would rather protein come from actual meat products, not by-products.

Fructooligosaccharides (FOS)

A prebiotic. Fuctooligosaccharides (FOS) are plant sugars that occur in a wide variety of fruits, vegetables, and cereals. They are produced commercially by partial hydrolysis of chicory inulin (an oligosaccharide found in chicory root), or from sucrose (sugar) using an enzymatic process. n addition to improving the digestibility of various food components, FOS may also improve absorption of dietary calcium, iron, and other important minerals.


Garlic is one of the most studied “health” supplements for fish food. It contains a compound called allicin which has numerous medicinal properties. It has been proven capable of reducing blood pressure, lowering cholesterol levels, is an antioxidant with significant anti-inflammatory properties, has antibiotic and antiparasitic properties, and can help detoxify heavy metals in the body, protecting against organ damaged from heavy metal toxicity.

In a study of rainbow trout infected with Aeromanas hydrophila, treated with garlic at doses of 0.5 and 1.0 g garlic per 100 g of feed, there was a reduction in mortalities to 4% compared with the controls (88%).

In a study of Asian sea bass infected with Vibrio harveyi, Garlic-added feed (at doses of 5g, 10 g, 15 g and 20 g/kg) led to increased survival for all treated groups and dose of garlic at 10 g/kg feed significantly improved survival to 83.35% compared with the controls (33.3%). In addition, there was a significant increase in growth, weight-gain and feed conversion in garlic-fed groups.

In a two month study of Rainbow Trout, the effects of garlic ((dosed at 10g/kg, 20g/kg, 30g/kg) ) on growth actors, hematological parameters, and body composition were evaluated. The results showed that, weight gain and growth performance of Rainbow Trout significantly increased in all groups fed on garlic. Protein content and ash contents in fish bodies were significantly higher in the group fed on diet containing 30 g/kg diet of garlic than all other groups. Total lipids content in fish body decreased in treatments and it was lower in fish fed on 30 g/kg.

An Egyptian study of 1,600 Nile Tilpia wer fed a garlic supplemented diet (10g/kg and 20g/kg) for 8 months. The Garlic supplement was discontinued and the fish subsequently (intentionally) infected with Aeromas hydrophilla. Survival rates in fish with a (previous) garlic supplemented diet were significantly higher than the control groups. Consequently, garlic improved growth performance.

Garlic has been proven effective at killing roundworms, Ascaris lumbricoides, the most common type of intestinal parasite.


A coagulant, leavening agent, and sequestrant. Used as a coagulant in Tofu. Added to fish pellets for the same purpose, as a binder. There are no known health risks associated with this additive.

Guar Gum

A natural thickening agent that improves shelf-life of the food. Also has health benefits. Recognized as safe.


A source of vitamin C


A naturally occuring amino acid synthesized by the body to aid in metabolizing food into energy. Used to treat fatty liver disease in cats and heart disease in dogs. Its existence in a fish food ingredient list is an indicator the food is low in meat protein as its primary purpose is as a supplement to poor meat source diets.


A lipid material composed of choline and inositol. A natural antioxidant, very beneficial

Lignin Sulfonate

A product manufactured from tree sap. It's added to fish food as a binder. More commonly used as dust control on gravel roads. It is an approved product for use in animal feeds but I have not found where it is authorized for human consumption.


Standard source, non-vitamin B-Complex metabolizes blood fats. Not really believed to provide much benefit and may result in negative side.


Manganous Oxide

Standard source of manganese, manganese is necessary to development of strong bones and enzyme activators, enhances immune system.

Marigold Powder

A source of lutein. However, its inclusion in fish food is mostly marketing as it is too costly to use in large enough of a quantity to provided definitive benefit.

Menadione Sodium Bisulfite

Menadione sodium bisulfate
Menadione sodium bisulfite
Menadione dimethylprimidinol sulfate
Menadione dimethylprimidinol sulfite
Menadione dimethylprimidinol bisulfite
Dimethylprimidinol sulfate
Dimethylprimidinol sulfite
Dimethylprimidinol bisulfate
Vitamin K supplement
Source of Vitamin K Activity

All of the above are synthetic forms of Vitamin K, a controversial ingredient that has been banned from human consumption. Unfortunately, despite natural alternatives (such as spinach and kelp), this product is found in almost all fish food.

A peer reviewed University of Oregon study identifies:

“Although allergic reaction is possible, there is no known toxicity associated with high doses of the phylloquinone (vitamin K1) or menaquinone (vitamin K2) forms of vitamin K. The same is not true for synthetic menadione (vitamin K3) and its derivatives. Menadione can interfere with the function of glutathione, one of the body's natural antioxidants, resulting in oxidative damage to cell membranes. Menadione given by injection has induced liver toxicity, jaundice, and hemolytic anemia (due to the rupture of red blood cells) in infants; therefore, menadione is no longer used for treatment of vitamin K deficiency. No tolerable upper level of intake has been established for vitamin K.”

The Material Data Safety Sheet for Menadione sodium bisulfite identifies:

“Potential Chronic Health Effects: CARCINOGENIC EFFECTS: 3 (Not classifiable for human.) by IARC. MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to kidneys, lungs, liver, mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage.”

Milt Meal

A dried product manufactured from fish male genitalia containing sperm.

Monobasic Calcium Phosphate

Added to fish food as leavening agent to cause baked goods to rise. Created by by treating pulverized phosphate rock with sulfuric acid or phosphoric acid. Also used as a fertilizer.

Monosodium Glutamate (MSG)

An ingredient added to fish foods as a flavor enhancer and preservative. There are many myths concerning MSG, the only one for which I've been able to find a factual bases is that some people are sensitive to MSG and it may cause headaches and/or “flushing” of the skin for these people. Other myths behind MSG have been debunked.


A water soluble B vitamin (B3).

Para-Aminobenzoic Acid (aka PABA)

A potassium salt that is a growth factor for certain bacteria that use it to synthesize folic acid. Promotes the growth of healthy tissue and aids in the prevention of vitamin B deficiencies. PABA itself is a synthetic vitamin. The natural version can be obtained from green leafy vegetables.

Ponceau 4R

A food coloring agent (for red color). A known carcinogen banned from human consumption in many countries, including the United States.

Propyl gallate

Chemical preservative, can cause digestive upset, stomach irritation

Pyridoxine Hydrochloride

Synthetic vitamin B6.

Red 3 Dye

A food coloring agent.. Recognized in 1990 by the FDA as a thyroid carcinogen in animals and is banned in cosmetics and externally applied drugs. What it's in: Sausage casings, oral medication, maraschino cherries, baked goods, candies. An ingredient to avoid. You fish does not care what color the pellets or flakes are.


Synthetic vitamin B2.

Salmon Oil

An excellent source of Omega 3. Preferred over “fish oil”.


An artificial sweetener. It is added to fish food as a flavoring agent and to retain moisture. Has a side effect of being a laxative. While generally safe, it's an ingredient I would prefer not to find in my fish food.


A natural source of vitamin K. Either spinach or kelp should be used instead of a synthetic vitamin K. Why any food manufacturer would use both (spinach/kelp and Menadione Sodium Bisulfite) is beyond my understanding, but they do.

Sucrose esters of fatty acids

Prepared from sucrose and methyl and ethyl esters of food fatty acids or by extraction from sucroglycerides. A source of sugar. Added to fish food as a flavoring agent and emulsifier. Found in a number of human products such as Jello Pudding.

Thiamine Mononitrate

A synthetic form of vitamin B1. Thiamine is easily destroyed by the cooking process so most dry foods will contain a supplemental form of vitamin B1.

Torula Dried Yeast

A by-product of  paper production produced from wood sugars. Used in fish food as a flavoring agent.

Vitamin a acetate

A synthetic form of vitamin A.

Yellow 5 lake

A coloring agent. Since it is a lake, salt has been added to it so it is insoluble in liquids. If you drink Mountain Dew, this is where the yellow color comes from. The potential exists for allergic reaction. In fish this would manifest as flashing behavior. Approved for use in cosmetics. Manufactured from coal tar.

Yellow Lake 6

A food coloring agent. Benzenesulphonic acid treated with hydrochloric acid and sodium nitrite. Since it is a lake, salt has been added to it so it is insoluble in liquids. Banned in Norway and Finland. May cause gastric upset and is potentially a carcinogen. An ingredient to avoid. Your fish does not care what color the food is.

Zinc Oxide

Standard source of zinc, protects against free radicals, essential to insulin formation and immune function.

Fish Food Ingredients Conclusion

We have established criteria for what we want to find in our fish food:

1. Absence of toxic, potentially toxic, and controversial ingredients

2. Aquatic Animal protein and Preferred Plant Proteins as the primary protein sources

3. A fully nutritious food to include necessary vitamins and minerals with natural sources preferred.

So what happens if you take these three simple and reasonable concepts and apply them to commonly purchased fish foods? The answer? Almost all fail. This is the sad aspect of our hobby. Unlike dog and cat food, where consumer demand has resulted in the availability of holistic foods that comply with the above criteria, no such demand exists for fish food and as a result, no such food exists. They are, after all, only fish. So the question is…. is there a market for such a food? Are we, as the purchasing public, willing to spend more for such a food? Thus far, the answer to that question is an emphatic no, or such a food would exist.

NLS manufactures a quality food. It meets two of the above criteria with flying colors. But it likely contains Ethoxyquin and synthetic vitamin K. Absent documentation from the manufacturer, it cannot recieve our highest rating.

Omega One meets possibly two of the above criteria but it too contains Ethoxyquin and synthetic vitamin K, so it fails.

Hikari meets one, possibly two, of the above criteria, and even though their foods do not contain Ethoxyquin, they do contain synthetic vitamin K. It's also questionable as to if the majority of proteins come from preferred protein sources.

Aqueon meets at least one of the above criteria, possibly two, and even though their foods do not contain Ethoxyquin, they do contain synthetic vitamin K and again, the binder, filler, and non-preferred protein ratio is higher than desired.

All Tetra products fail the first two of the above listed criteria miserably, many fail all three, and the quality of their utilized fish meals is questionable.

The Zoo Med line of flake food passes all three criteria. Each of the Zoo Med foods are free of Ethoxyquin, synthetic vitamin K, and artificial coloring, while the primary protein sources are what we want. At least we have a food for our flake eating fish but that does little for our large pellet eating fish. But even with Zoo Med, the quantity of non-preferred proteins can be considered more than desired and the salmon meal utilized is comprised of farmed salmon.

Even high-end, harder to find “gourmet” foods such as Dianichi and XTreme Aquatics use fish meal instead of preferred Whole Fish, with non-preferred protein quantities that are more than desired, and it has not been confirmed that these foods do not utilize artificial colors or Ethoxyquin.

Only Northfin (thus far) meets all three criteria, which is why it is the only six star food. But it can be difficult to obtain and may be prohibitively expensive for many in our hobby.

So after a full analysis of the ingredients of fish foods, we are left with no alternative but deciding which of the three criteria is the least important. Which means you will have to scratch one of the three requirements in order to continue feeding an easy to use dry diet. Unless, of course, enough of a demand is made upon fish food manufacturers to generate a market for a pellet food that meets all three criteria.

Myself, I am moving my Oscar over from a diet of about 90% pellets to one that is closer to 40% pellets, increasing the use of frozen foods. I refuse to feed a food that contains Ethoxyquin or artificial coloring. Of course, I would be irresponsible if I did not conclude this statement with an adequate warning. Such a diet is potentially more dangerous than is a dry food diet containing the ingredients I am trying to avoid. It can be too high in fat and limited in vital vitamins, such as Vitamin C. It certainly requires more effort and thought than is involved in feeding a simple pellet.

Hopefully, at some point in the future, our hobby creates a demand for a holistic food that meets our criteria. Without the demand, it will never occur, and we are forced to feed a diet that presents potential health risks to our fish.

1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 5.00 out of 5)

Leave a Reply

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail.