You are running them in series I take it?
Yes its normal that the waste water TDS would double. You are essentially taking the concentrated TDS of each membranes rejection and combining them.
Are you using resin for your last stage?
hello guys .. So few days ago i upgraded my RO/DI with another membrane (100GPH) now the waste water from RO comes out 300+ TDS (Befor was 175 or so ) and clean water arround 10-20 TDS (Befor upgrade 0 ) water from my tap has 170 ish tds ... the pressure what feeds my first membrane is arround 60 psi ! is it normal that waste water comes out double that before ?!
You are running them in series I take it?
Yes its normal that the waste water TDS would double. You are essentially taking the concentrated TDS of each membranes rejection and combining them.
Are you using resin for your last stage?
Last edited by Neptune; 04-30-2017 at 10:35 PM.