black mold looking stuff

[jnvette]

my friend has a couple of plants in his tank and they startred to grow this black hairy mold looking stuff.the algae eater wont even touch it.what is it?should he be concerned?

 

[malkore]

sounds like brush or beard algae...likely they have high phosphates in the tank.

 

[betowess]

Yeah, sounds like BBA (Black Brush Algae) which is actually a red algae. It prefers alkaline water and is hard to get rid of except with CO2 kept at 30ppm, in my experience. But you can slow it down with frequent water changes and thoroughly cleaning or pruning where it grows. There are some pretty good articles in the Krib (online) about dealing with BBA. But 30 ppm was my silver bullet which Rex Grigg turned me onto. Good luck.