I have beatiful pink zoo's I bought for my daughter. They have always been full and heathy, but I have them wedged in creating and overhang. They completely cover the rock they're on. Should I move them where I can put rocks surrounding them so they will spead on them or will they either "jump" or "drip" off of the over hang rock? I will post a pic if I can. Also I hear they like "dirty" water. How do I help with that requirement?