[GS-Rock]

well it shouldent matter what it is, if you want the algae dead, remove the rock, let it dry out and try to get it off with a hard brush, before putting it back in your tank make sure its all gone, try vingar if your haing trouble getting it off, or you can go a easy method and take the rock out and put it in a bucket and cure the rock, every thing on the rock will die with in 4 weeks of darkness better yet should die. You should also see into getting a good test kit, you can do your first test on the rock, do it once a week and check the readings on it, after 4 weeks in the bucket check it out and see if it died, try cleaning the rock with a hard brush, if its not dead do a water change in the bucket and try again for 2 weeks or so. also doing this will turn your live rock into DEAD ROCK, but once its dead it will reseed with your other rocks after some time