I have two questions, First, we bought a toadstool (leather?) and we are not sure how much water flow we need. How much should the polyps be moving? Yesterday It had cobweb looking gunk on him so I increased the water flow and it washed them off. My second question is about skimming. My skimmer collection cup fills up with green gunk but at the fish store, their collection cups have brown gunk in them. Is this determined by food? Thanks for the help! Maybe someday I'll be able to answer questions 8)