Originally Posted by Eggpaul
Yes, I heard of peroxide. Would it hurt my coral if some dropped on it?
That depends on the coral. Stony corals are not friends with peroxide. But, really nothing is in this case. I have submerged zoas into it and thought that they were dead...but several days later opened up. I have used an electric toothbrush being dipped into peroxide or peroxide solution to get at the algae issues close to the growth of stony corals without damaging them. Right away it doesn't look like anything was solved, but in a couple of days the algae will be gone.