I have a 75gpd 4 stage BRS ro/di system. Just out of curiosity I checked to see how much waste water I was putting out for every gallon of good water and I was surprised that it put out 5 gallons of waste for just 1 Good gallon. Doesn't this seem like a lot? I am running at about 50 psi. Anybody else seen this before or is this normal or any ideas what to check or replace?