75 GPD DOW Filmtech Membrane Only $38.00!!! Our 75 GPD membrane fits most standard residential style membrane housings. Your purchase includes one 75 GPD Thin Film Composite membrane with a 1 year Waranty. In other words if your membrane fails within 1 year we will replace it at no cost to you! ***FREE SHIPPING*** 3reef.com users your exclusive coupon code "3reef-5off", just enter the code at checkout to receive 5% off on everything in the store!