Aquatic Life Flush Valve Assembly. The flush valve assembly is designed to flush the membrane and clear any debris that may have been built-up on the membrane. Doing this on a regular basis will prolong the life of the membrane. See the instruction sheet on the ADDITIONAL INFO for instructions on how to assemble the flush valve kit. To flush your membrane, simply open the valve and allow the water to bypass the Flow Restrictor. This will allow the water to flow quickly around the outside of your membrane and help sweep away any build-up. Flush the membrane for 30-45 seconds prior to each time you use the RO unit. Item 500394.