are all ro membranes the same size? will a 35, 75, 150 membrane fit in the same unit? and does a 150gpd mean you can save more water then the 75 because water is permeating through the membrane more?
They are all a standard size membrane. Well most unles you get some off the wall under sink deal. But yes either rating will fitt in the same housing.
You will not save any water. Typicaly any ro membrane will make 4gls of waste water for every 1gl of product water. The difference is the time it will do so.
Water pressure and water temp also effect the efficiency of the RO membrane. Cold water will filter better but also slower. Low water pressure will filter very slow and not as well. You should use cold water at 60+ psi for best results.
