I have two yuma's I can't get to attach to anything. One is about the size of a dime, the other the size of a silver dollar. I've got them in an acclimation type box in the tank with rubble rock and shells. It's been about two weeks and they refuse to attach. I've used this method with regular mushrooms and they attach in about a day or two. Is there anything else I can try? I've had more success getting a Yuma to attach to a moving snail then to anything else.