I have a T1000 use the boxes and bring the water level half way up the outlet tube. If you don't have the boxes than you have to raise the water level to just below the neck I believe it will be around the 12" level I asked Carmen to measure her level on hers and that is what she runs hers at. I believe it was Carmen. Once they are working they produce realy dark skimm and it smells I cleaned mine the other night and it turned the water inthe toilet black-green had to flush twice to get clear water. The small hung around for a couple hours. I don't think I'd go to a different skimmer if I do buy anouther skimmer it will by the T5000.

Bill