All the above is true. I have used FWE three time now and some died, but they are on steroids now. Not for one minute think that are harmless, ever see a normal red mushroom covers in about 50 little bastards, I have a 180gl, full of softies. leathers so irritated, they shed, and shrink. Mushrooms verily open...get them out. I will have to have tank maintenance until they are handled. Two fish didn't take well to the treatment, so I wont do it again.nGood luck, get it handled.