RO output?

[BCreefmaker]

my ro/di is seeming to put out more then what its rated for??? is this normal? i tested both the in and out water- 46 ppm in : 1 ppm out. is it because the unit is rated for the intake water to be 200ppm and because its cleaner the membrane works better?

 

[AZDesertRat]

Two things have a big effect on RO output, water pressure and temperature. Depending on which membrane you have it gets its rated output at 50 psi (Dow Filmtec) or 60-65 psi (Applied Membranes and GE Osmonics). It is also rated at 77 degrees F so if you have higher temperature or pressure thats why you are getting more. Excess pressure is not really much of a problem as membranes are rated at 300 psi (housings and fittings are only rated for 125 though). Excess temperature is a big big concern though as 113 degrees is the absolute highest they can go without melting and 80 to 90 is about as high as you want to be continously. www.buckeyefieldsupply.com has a nice calculator that helps to figure correct outputs.

Did you test the RO only TDS without DI to make sure it is functioning and the DI is not doing everything? It can happen.

 

[BCreefmaker]

humm il give that a try...

 

[rbursek]

Being in BC Canada what is your water supply from? I agree with temp, but I am guessing you have well water and that runs 56*F,
my unit puts out less for that reason, even if it is "city water" with the piping under ground I would think in the summer it is no warmer then 65*F. I agree with AZdesertrat if one of those cartridges in not in right you are bypassing it.
Bob