I just didn't want to take the chance. When I moved the moss, it was everywhere, along with some fuzzy mould. I did not have an inch of that tank that did not have fungi growing. I didn't mind the little mushrooms, but this stuff did not look the same at all. I included a couple of pics. I was amazed at just how much of it there was, and having recently lost a toad in that tank, I needed to make sure the rest of my toads would not get sick.