Just remember to ALWAYS top off BEFORE you attempt to adjust the skimmer. Over the coarse of a few days, I would always adjust the Prizm to the point I was getting a full collection cup of skimmate a day. That way, I always new I was getting everything out of the device I could, as emptying the skimmer once a day was all I had time for. Ofcoarse you can forget the dry foam hype companies use to market skimmers, just shoot for murky brown green water, and do clean the collection cup every few days. My prizm did as bout as well as my Aqua C Remora, it just required more tinkering, but it also cost 3 times what the Prizm cost, so theres a trade off.