This is a discussion on Black fuzzy fungus? within the Beginner Planted Aquarium forums, part of the Beginner Freshwater Aquarium category; -->
Some of my plant leaves have this brown/black fuzzy fungus looking growth on them. They are actively growing but I don't know if this ...
Some of my plant leaves have this brown/black fuzzy fungus looking growth on them. They are actively growing but I don't know if this will harm them or my tank. I have a T5 and my plants are low light cabombas, ludwigia, rotala, bacopas and crypts. Could this be an illness? Is there treatment to remove this fungus looking growth? Posted via Mobile Device
Could you give a little more description of the "fungus" appearance and the tank conditions? Is it a brown coating on the plants (that you can gently wipes from the leaves), or does it look like small paintbrush bristles? Is it a new tank, what size tank, do you fertilize, light duration/day, have conditions changed recently in the tank?
Also, I have never heard of a "low-light" Cabomba. You may have more light in the tank than you think!
I missed a comma there, sorry. It is coating the leaves, like moss on a tree, and on my crypt it sprouted a small growth that looks like round brush bristles. Its not a new tank. I've had it set up for about six months. The plants are fairly new. I fertilize with flourish once a week. Its a 20 gallon that gets about ten hours of light per day. I have taken some fish out of the tank, not diseased related, simply rehomed; but the brown growtnh started before the move. Posted via Mobile Device
I agree it is likely some type of brush algae. This is actually a red algae, but in most tanks it looks dark brown or black, sometimes very dark green/grayish. I have fought this algae several times, and it is now under control.
It is due to the light and/or nutrients being more than what the plants can utilize. Unfortunately it will continue to spread over every plant leaf until the plants are all dead, if not checked.
The way to deal with it is to create a balance between light and nutrients. From what you've told us, you have a T5 fluorescent tube over the tank. Is this HO or NO? And what is the Kelvin rating?
On the nutrients, what is the GH of your source water? And how frequent are water changes, and how much volume?
Is you tank a 20 high or long? You likely have a lot of light either way, but certainly too much for a 20L, which isn't a deep tank. I'd drop the photoperiod to 8 hours/day at a minimum no matter what. You say "about" 10 hours. If you don't use one already, pick up a light timer!
I agree. But I'm a bit confused over the light...T8 does not come in HO, it is basic fluorescent. T5 has HO (high output) and NO (normal output, which is roughly equal to the same length T8 tube). Anyway, reduce the light down to 8 hours.
I'd still want to know the GH though, as this is a source for the "hard" minerals that are insufficient in Flourish. Part of that balance again.