Q. My sword plants are developing a black fuzz on them. I use Seachem Excel, Potassium, Flourish, Algaefix, Stress Coat and Stresszyme. Is there anything else I can do?
A. The black fuzz sounds like BBA and can be a pernicious pest. There are a few things you can do to be rid of it, and unfortunately the first step is cleaning. It is not easily removed, except by pruning away the infested leaves, removing affected hardware or driftwood, and scrubbing it clean. Gravel can be cleaned by removing portions, stirring it in just enough water to keep it slightly “fluid” and rinsing it. The stirring works the gravel grains against one another and scrubs the algae loose, while the rinsing carries it away.
Cleaning will be a disappointment, though, and the algae will keep growing back, unless you can correct the conditions that allowed the tufts to grow and multiply. Excel provides a source of carbon that can supplement the normal sourcing from carbon dioxide in the water. Adding carbon dioxide is much better and has a greater effect. Black beard algae doesn’t seem to grow well in aquariums that maintain high levels of carbon dioxide (15 to 30 parts per million [ppm]). You can add carbon dioxide with a fermentation reactor or with a compressed gas cylinder. Feed either one into a commercially available “injector,” air stone or reactor. I like external reactors because they mean less visible equipment in the aquarium. I have also found that BBA takes hold in aquariums that have accumulated a lot of dissolved organic material. This is easily corrected through frequent large water changes, which are a good idea anyhow, especially if you are dosing macronutrients (potassium, nitrogen, and phosphate). Ensuring that your aquarium has adequate macronutrients is also important for avoiding most kinds of algae that commonly grow in aquaria. SeaChem Flourish is a trace nutrient source. You can get commercially available aquatic plant fertilizers that provide macronutrients, too.
I was hesitant to do frequent large water changes when first advised to use dosing and large water changes. However, I’ve been doing it for years and have never seen a sign of stress in a single fish. Actually, I think stress is more likely to occur in aquariums without water changes if dissolved organics are allowed to accumulate.
I believe algae growth occurs most often because of a lack of one or more macronutrients rather than a mere excess of nutrients. If any one of the three macronutrients is not in adequate supply, the aquatic plants will not be able to use the other two. Put a phosphate absorber in your filter, and watch your plants slowly worsen and your nitrates climb!
You do not want too much. Too much of anything is not a good thing, and too much nitrate will result in a lot of green algae on the planted aquarium glass; and if the amount grows excessively, you’ll get green water. However, if the level of nitrate stays around 5 to 10 ppm, the aquatic plants will do well, and the algae will have a hard time getting a foothold. Similarly, phosphate levels around 0.5 to 1.0 ppm will not be a problem, but having less will be a problem. If there is too little, the aquatic plants will be hungry, and won’t be able to use up the nitrates or potassium. A potassium level of roughly 20 ppm is good..
These recommendations are for fast-growth, high-lighting- level aquaria with more than 2 watts of light per gallon. This might seem to be too complicated and too much work. However, there is an alternative: Lower the lighting level to 1.5 to 2 watts per gallon, and enjoy a slower-growing planted aquarium.
Also, Siamese algae-eaters (also called SAEs) can be a great addition to help keep BBA at bay. They will do some of the cleanup in your planted aquarium, and more importantly, will eat anything that grows as fast as it grows. So, they keep the little “paintbrushes” from spoiling your aquascape. You can find a lot of information on these fish if you search the Internet for the terms “Crossocheilus siamensis,” “Siamese algae eater,” “Neil Frank” and “Liisa Sarakontu” (Neil Frank and Liisa Sarakontu wrote an article talking about this species in 1995, “Algae Eating Cyprinids from Thailand and Neighboring Areas,” The Aquatic Gardener. 8 ).
A few years ago, these fish were hard to find, but they are much more common now. They are sometimes sold under the common names of “flying fox,” “false flying fox” and “pink fox” (although they are not pink). Their appearance is similar to the Epalzeorhynchus kalopterus, which is also sold under the name “flying fox” (and sometimes “false flying fox”) and has a similar bold black stripe running the length of its body. Of the two, only the Crossocheilus’ black stripe extends all the way into the tail fin.
I cannot comment on the other chemical products you mentioned because I have never used them.