I hooked up a sand filter and then a cartridge filter behind that. I love it. The sand takes the big stuff out and the cartridge is like a polishing filter for the little tiny stuff. I have not seen a pressure drop or increase. I only cleaned my cartridge filter twice the whole season. I love it. I run BBB and salt for softness. My wife says our pool water is cleaner, clearer and smells better than any of the pools at the resorts we go to.