moss/algae control

[cejones94]

I have greenish black stuff growing on my rocks. What is it..is it harmful to the fish? It doesn't go away unless I scrub the rocks. Is there something else I can try

 

[cejones94]

Here are some pics of it somewhat cleaned up

 

[RussellC]

I have greenish black stuff growing on my rocks. What is it..is it harmful to the fish? It doesn't go away unless I scrub the rocks. Is there something else I can try

It's hard to tell from the picture, but it looks to me like brown algae (diatoms).

This kind of algae is common in aquariums, and the good news is, it isn't harmful to fish. Physically removing it from the rocks is a fine option for getting rid of it.

This kind of algae is also common in newly cycling tanks. If your tank is young, this algae may simply disappear on its own once your aquarium's cycle becomes more established.

Either way, though, aside from being unsightly, it poses no health thread to your fish.