Brown Coating

[reefin geek]

Forgive my laziness for not doing a search on this.
My LR is getting covered by a brown coating, with sort of a clear film on it.
The tank is about 7 months old, all params seem to be in check.
I use RO water for topoff and I dose KW every night.
What would this be and how can I get rid/control it?

 

[jdeets]

I've got some of that growing in my tank. It's a kind of brown algae that seems to be a lot denser than diatoms. I think you can scrub it off the rocks if it gets out of control. I'm leaving mine alone for a while, because some of it seems to be getting covered up with coralline algae. If it gets out of hand, then I'll go in with the toothbrush...

 

[jmeader]

What would we do without our toothbrushes?