please ID

[wilson717]

Please help me id what this brown matter on my lr. It has tiny bubbles that come up from it. It is a rust color. It does not blow off it has to be scrubbed off.
Is it good or bad?

 

[symon]

There are lots of alges that start out looking like that! Check your Nitrates , check your Phosphates! Find the source of the alge!
Nitrates generally means overfeeding!
Phosphates generally means cruddy water, The RO water i was buying had higher PH then my tap water! But i have copper lines so i can't use my water!

 

[cabin7882]

I thought that is what is supposed to happen to the rock it turns brown to dark brown then eventually dark purple? Atleast that's what I've heard

 

[isistius]

how old is your tank? if it's new, then it's probably diatoms. just part of the nitrate cycle. they will eventually go away...