I have two questions. I am somewhat new to the hobby and have recently purchased red cherry shrimp, and want to get 3 dwarf mexican crayfish. I did have a crayfish a few weeks ago, but he suddenly became very sick and despite all efforts to help him, he died. I thought he was molting, so I just kept an eye on him and left him to do his thing. However, quite quickly I noticed he was not shedding the shell but rather it appeared to be growing. I only realized too late it was not molting but may have been a white, fuzzy fungus or something I noticed to be on the wood in my tank. What is that stuff? I have pima and mela fix but that didnt help. What do I do to rid my tank of it? Second question. I cant seem to find a good food that will be suitable for both the little shrimps and the crayfish. All the foods I find have copper sulfate. Is this ok for shrimps? Can someone recommend a brand of food that is good for both and complete nutrition? Thanks everybody for your help.