Black algae on my rocks?

[neilsarah]

So I have never came across an algae that looks like this before. I also have never had a tank this big before. I have a 195 gallon with Malawi gaps and peacocks. 3 plecos and 2 syno cats. All water parameters are in the normal range and tank has been established for well over a year. I have read some things about co2 levels causing this as well as lighting issues. Anyone have any thoughts/suggestions? Thanks in advance for the help.

[Ron]

Look up "black brush algae", "black beard algae", or "black bush algae" for more details on what to do next.

... on my non-planted tanks, I just learn to accept it.

[Thriftyfisher]

I have found that if you stick pothos roots into the tank it will go away in time.  I don't have as big of a tank as you do but it works very quickly on a 29 gallon tank, like in a month. the roots will eventually grow down to the substrate.  However, I haven't used it in tanks where fish eat plants so if you have plant eating fish Cichlids, it may not work as well.

[mibwb]

I have that in some tanks...it seems to really like to grow on the pleco caves. It seems to do no harm. I just take the caves and scrub it off now and then...no big deal. If it seems to really like a cave...I'll bleach it.