Using Hydrogen Peroxide (H2O2) On Black Beard Algae (BBA)
There is no algae that causes me more grief than black beard algae aka BBA. I've researched and read many opinions on what causes BBA, but I've yet to find a clear answer. In fact, the answers are often conflicting citing variables like flow, nutrients, lights, CO2 i.e. basically everything common to a planted tank setup.
My own experience with BBA shows that:
- BBA grows in high and low flow areas.
- BBA primarily grows on my driftwood, but it also shows up on the top of the leaves of vallisneria and on slow-growing plants.
- BBA isn't affected much by light intensity as I have it growing at all levels from the substrate to the surface.
- Otocinclus, Amano Shrimp, and Nerite Snails won't eat BBA.
- Daily, double-dosing of Excel doesn't keep BBA at bay. Although it does stop staghorn algae fairly well.
- I get BBA even though my pH and CO2 levels are kept steady via a pH controller.
The only success I've had is with hydrogen peroxide particularly when I use it for spot treatments. I have two methods for spot treating. Regardless of the approach I use about 1 ml of hydrogen peroxide per 2 gallons of water.
- For areas of my aquarium that can be exposed with water changes, I will use a spray bottle to cover the BBA with hydrogen peroxide.
- For areas that can't be exposed, I deliver the hydrogen peroxide using a turkey baster with a thin straw attached to the end to give me more reach and precision. This has worked very well on filter components, the top of my heater, and on driftwood. I'm experimenting with this approach on plant leaves (see images to the right). So far I've managed to kill the BBA (it turns pink), but the verdict isn't in on whether I'm significantly damaging the plant leaves.
Things I've Yet To Try
At the moment I'm able to limit the BBA growth with hydrogen peroxide, but if things get worse I may consider these other approaches:
- I've read that people have used 2 ml per gallon with no ill effects, but I'm nervous about going that high.
- I've also read about a “one-two punch” that combines hydrogen peroxide and Seachem Excel in a whole tank treatment, but my situation isn't bad enough to warrant taking that kind of risk.
- Someone reported success using Seachem's Phosguard, but the explanation for why it works doesn't make sense to me. Replies in the thread also show there is disagreement. Still, counter-intuitive things do sometimes work.