Review on Streamline Your RO System with Quick Connect Fittings for Reverse Osmosis Membrane by Chelsea Miller

Unlike most older diaphragm housings, this one does NOT have a check valve in the clean water outlet line. The absence of a check valve allows purified water to flow back into the housing and out of the channel when the drain shut-off valve is closed! This causes the R/O system to waste a large amount of water by constantly turning it on and off. The seller points this out and says you may need to replace the check valve. The need for a check valve should be included in the system requirements.