I'll check with Ray, thanks. I'm likely going to continue to use my 250 Deer Run until I get old enough that I decide to quit, since I've cut back from 1320 taps. I did finally buy a new set of MES membranes because I detected some funky growth in my permeate tank about 2-3 mos. after the season in a tank with 4-500 gal held for other uses. That told me that even though I got a zero sugar reading in my permeate water even when concentrated to 1/10 original volume it was passing some sugar, since the permeate tank is a fully enclosed 1000 gal SS tank.