Live rock and Crab shell turning copper?

[baronessbuni]

Ok so this tank is fairly new (about 3 weeks the fish have been in it) I tested PH, Nitrate, Nitrites, Ammonia and everything seems to be ok, but the live rock and the crab shell are turning coppery in color..as well as some of the rock at the bottom of the tank. Fish look ok (just have a damsel, clownfish and the crab in there) but im concerned about the changes in color over the last week. Anyone have any idea of what to test for ir if there is even anything wrong with the tank?
Thanks

 

[subielover]

Sounds like diatoms to me, your clean up crew should take care of it. It is part of setting up a new tank, most of us have been through it, no biggie.

 

[baronessbuni]

All i have is the crab in there, should i be getting something else to help?

 

[subielover]

Yeah, I don't think you mentioned the size of your tank though. You definitely are going to want to add some snails, nassarius, cerith, astrea, turbo, etc, a nice mix of them should help eat the diatoms. Also fighting conches do a great job at eating diatoms off the sand bed.