RODI

jmags080307 · Jun 13, 2016

I changed my di resin out and it's testing at 11?? I had water from my LFS and that tested at 1 with the same meter. My tap water tests around 420. Without the di resin filter in my water tested at 33. When I first got my rodi system my water tested at 0? I'm using a spectrapure di resin filter. Any thoughts would help.

reef_junkie · Jun 13, 2016

What about your carbon and sediment blocks?

AZDesertRat · Jun 13, 2016

Sediment and carbon filters have nothing to do with TDS.
Is the replacement DI cartridge brand new and fresh? How long have you had it, is it still in the unopened mylar foil bag and how was it stored since you bought it?

How long did you wait before testing the TDS from the new cartridge? Did you run a good gallon or two through it before testing?

Did you test the tap TDS, RO only TDS and RO/DI TDS all at the same time? Did you rinse the clear glass you are testing in and TDS meter in distilled water or known 0 TDS RO /DI water between each test so you know the meter and glass are clean and not interfering with readings?

jmags080307 · Jun 13, 2016

The DI cartridge is brand new and fresh. I bought it Saturday and it was in the mylar foil bag unopened and put it in same day. I have run about 2 gallons through. I'll go through the testing u propose. Thabks.

AZDesertRat · Jun 14, 2016

Did you buy the DI cartridge from a retail store? It may have been sitting on a shelf for 6 months and be exhausted. I am particular about my DI so do not buy in bulk or from a retail store, you never know what you are getting. I have a good idea how long my DI lasts so don't order a replacement until I know I am close then store it in the refrigerator until I open it.

jmags080307 · Jun 14, 2016

Ran it for about 30 minutes with the 70 degree water and I'm now registering at 2ppm. Previously I would ran it with only the cold water on at probably 60 degrees or so. Thanks!

AZDesertRat · Jun 15, 2016

Use only cold water, never try to temper or blend hot and cold.
Cold water actually treats better and will give you lower TDS. It is less viscous, more dense, so the contaminants do not flow through the RO membrane as easily giving you a better rejection rate.