RO Help

[APW]

I change both membranes on my RO system. Also changed the pre filters. My product is 2 and 1/4 gallons and the reject is 3 and 1/4 gallons. The pressure is at 200 PSI. The product water is 7ppm. This Product water used to be down to 2ppm. Any suggestions?

 

[MEP001]

7 ppm is still very good. It's most likely just something different about the new membranes, and it might even drop over time. The new ones are coated with an algaecide that needs to flush out.

Have you checked your water softness? That can affect the RO quality.

Why did you change the membranes?

 

[APW]

I have a dual tank softener and the water is at 2 grains. I pulled the membranes up an down and twisted them to make sure they were sealing good and I was able to get it down to 4 grains.

I changed them because the TDS started creeping up (it was at 2 when I started the RO unit up a 1.5 years ago and it had gotten to 6. I have two other locations where one of the RO systems is 2 and the other is always 0.

This location has two 10" prefilters before the RO unit so I changed them yesterday and the second filter was very slick not slimy but almost a slimy feel. I do have a charcoal prefilter in line before the unit which I put new charcoal in when I first started this unit up. This is a a old Dilling Harris unit I rebuilt when I opened this location.

 

[MEP001]

I pulled the membranes up an down and twisted them to make sure they were sealing good and I was able to get it down to 4 grains.

I was going to suggest that next. If you're not happy with 4 ppm and you didn't clean and lubricate the o-rings that seal against the tubes on the ends of the membranes, that should improve the seal.