I have one on my 75 gallon and it works great. It will take a while to get it adjusted properly, but most do anyway. If you're handy, I would sugest making an overflow for your waste cup. You simply buy a brass valve (from HD or?) and drill a hole into the cup, thread the valve, seal it with silicone, and then run some hose into what ever. I personaly use a one gallon milk jug. This way, I do not have to empty the collection cup about one a month.