This may sound like a dumb question, but here goes. Have a Spectrapure Unit, and I got a Flush Valve with it, although I have no idea how to hook it up. Need some help. Thanks.
The flush kit goes on the "dirty water" exhaust from the RO. The point of the flush valve is that you open the valve to let water bypass the flow restrictor. That flushes the membrane.
That is the concept. Your exact plumbing will depend on your system.
If your system is like mine, the flush valve goes onto the yellow dirty water line coming from the top, left, portion of the membrane cannister. The flow restrictor goes throught the long loop (can be a little tricky to feed through) When the valve is opened, water flows at a higher rate and lower pressure across the outside of the membrane and carries away particles which are plugging the membrane. I found the main problem in my system was extremely hard water which caused calcium carbonate deposits to clog the membrane. I had to spend $1000 on a high quality water softener to finally solve the problem. My membranes were only lasting for about 500 gallons prior to adding the softener.