The ETSS skimmers rock! I own 2 of them and they beat anything else in there size. Very effective, and pull gallons of nasty skimate, but they do require bigger pumps to operate correctly. The smaller ones work fine with a mag drive, but a pressure pump is required to work with the larger downdraft skimmers they offer. They definitely work as advertised, but do cost more to operate. Support at ETSS is very helpful and can recommend a skimmer to fit your requirements. They were very helpful when I had questions both before and after the sale.