brown on rocks?

Since you said it's brown and also on your glass I would say it's diatom algae- quite common in new set-ups.
 
That is certainly just the diatom's. Pretty common. My tank has a CUC that keep mine in check. No problems..it won't kill your fish. Tons of ways to get rid of it, just search on the site..and see what works for you.

Saltie
 
If it's a new tank, then the brown algae (diatoms) is completely normal,

I agree its pretty common with new tanks - My new 75g was set up 4 weeks ago, the last two days the brown algae is spreading like wildfire, rocks, plants, decorations, glass - it's getting out of hand quickly. Time to fight back. :)
 
well i did check everything and the only thing th at is high is my nitrates by a little. I went out and bought this algone product to get rid of this problem i been doing 30% water changes constantly. Does this effect my LR at all it already looks like no life on it so far
 
If you are doing lots of 30% water changes and it is not coming in check, are you using tap water with a chemical to remove nitrates?

I was doing that and had major diatom problems, I got my RO/DI system setup and the brown algae seems to be slowing down some.
 
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