I run a 200gpd system with an 85psi booster pump with 2x100gpd membranes in parallel. I have just changed the prefilters (ran them for a while to clear sediment etc...) and the TDS after the RO is 22. My question is, should 2 membranes in parallel produce the same resultant TDS i.e approx 7-10tds in total..........or, is each producing approx 11 tds and its doubling up to produce 22 ??
I have changed prefilters and resin, but after producing 1000 litres, the tds has crept up to 002 after 2x700ml DI units. I'm wondering if the DI is struggling to get the 022tds down, and hence "wearing" the resin out quicker.
The 100 gpd membranes are approx 10 months old.
Would you suggest changing the membranes..........or am I asking to too much to keep the tds to 000 after 1000 litres
Hope that all makes sense.
Thanks
Fieldsy.