what is this brown stuff in my salt water tank?
I came home after two days (and a friend looking after my fish) to find brown stuff on my live rock and on the gravel/substrate.
It is only a new tank, live rock was in there for about 10 days before I added fish. I added the fish and a small coral 4 days ago (2 clowns and a yellow goby) and they were fine for 2 days, i fed them on friday, frozen mysis shrimp. I just returned, Sunday, to find brown 'stuff' on my live rock and in the sand....
Is this normal?
Is this fish waste? or algae?? or something?