I went home for lunch, and found my sargasssum fish on the ground. He is very dark (he changes to a dark brown when unhappy) and there is a greyish film on the top portion of his body. I treated the tank with greenex, it has worked before and it is all I have at the moment. He looks real rough, barely moving, just kind of floating there. What is this. I am not sure, but I think it is ooidium? He was fine yesterday, I did not check him this morning, but when I went home there he was. Please let me know what this could be. I have had him a long time and would hate to lose him.
