DL, I like the gast pump, plus I picked it up for $20 bucks! I am running 4 dual 9 inch membrane diffusers, each diffuser is about 250 to 300 feet from pump at about 12 foot deep, the pump works great. I added high temp hose between ball valves & poly & this solved my issue. I had swicthed to a premade manifold with ball valves used in radiant flooring, but it caused too much air friction! I went back to the old set up.
