So after several weeks of nothing but water overflowing into the skimmer collection cup and lots of water changes it seems to be that my water conditioner is causing the problem. I discovered this after finally getting the skimmer working only to have it fail almost instantly when I topped up the tank with water that did have conditioner in it. So I ask you. Anyone else have these problems and what are you using that does work. I have a psk - 75h http://www.eshopps.com/hangskimmers.php . Are skimmers individuals when it comes to this kind of thing?