I was surfing the web recently and found the Everpure MRS-600 - a commercial food service RO system. What was noteworthy was:
"When comparing the ratio of waste water to permeate (or usable) water produced, conventional RO systems are typically only about 20% efficient. The MRS-600 on the other hand, has an efficiency of nearly 80%!"
"In fact, with conventional RO systems, nearly four gallons of water go to drain for every gallon of pure product quality water produced."
"The MRS-Envi-RO produces up to four gallons of pure product water for every one gallon of water going to drain."
Obviously, a commercial RO is too $$$ for residential applications. However, it made me curious as to what currently is the most efficient residential RO system?