RO/DI--people who have it can you help me?

[littlesilvermax]

Originally Posted by sharuq1

TDS there is 18. The unit is supposed to be 100gpd. Also TDS before "polishing" filter (after DI) is same as what is coming out when polishing filter is hooked up, so guess it isn't that.

If your post RO tds is 18 ppm, then you have one of three things:

1) very high tds water (like 600 or so) and it exhausts your DI quickly
2) a bad membrane (FWIW the 75 gpd, I like the Filmtec, seem to consistently outperform the 100 gpd ones)
3) very low pressure to the unit

How to solve the problems:

1) just have to live with it (BTW someone around here has awesome deals on DI resin)
2) get a new mambrane, and by the sounds of how much you are using stick with the 75 gpd ones
3) get a booster pump

FWIW even if your pressure is good, a booster pump wil up efficiency, that is why I bought one.