Sounds like possible cyanobacteria "red slime"? If it is try Boyds chem/clean. In my expierence it is safe for all corals fish and invertebrates.Just One thing- Dont shut down your skimmer though!I did the first time I treated and it was not good.(my fish died of lack of oxygen) just follow all the other directions exact,I used alittle less than called for since I was afraid to use it at first howeever it really did get rid of the cyanobacteria with 2 treatmments 2 days apart and I cut back my light to 6 hours a day while I was treating the tank,that really seemed to help knock it out the less light combined with the treatment stopped the cycle.I
Sounds like possible cyanobacteria "red slime"? If it is try Boyds chem/clean. In my expierence it is safe for all corals fish and invertebrates.Just One thing- Dont shut down your skimmer though!I did the first time I treated and it was not good.(my fish died of lack of oxygen) just follow all the other directions exact,I used alittle less than called for since I was afraid to use it at first howeever it really did get rid of the cyanobacteria with 2 treatmments 2 days apart and I cut back my light to 6 hours a day while I was treating the tank,that really seemed to help knock it out the less light combined with the treatment stopped the cycle.My tank got it at about 3 months..
I am willing to bet on cyano too, but I can't advocate using another chemical to treat a normal occurrence in a new tank. I'd try large water changes first, test for phosphorous and high nitrate levels (or other nitrogenous wastes).
