When/What filter to change?

[Steveg229]

I have been using my 5-stage RODI unit for about 6 months now. I recently purchased a TDS meter and calibration solution. After calibrating here are the test results.

Tap water- 761 ppm
After RO- 42 ppm
After DI- 19 ppm

I was pretty surprised that I got such high readings, I was hoping for 0 after DI. Is it time to change the DI filter or all of them?

Is the DI 19 ppm because the tap water is so high??

 

[bjohanson1234]

Wow that is high incoming TDS!!!!!
Without knowing where you started, it is hard to tell if it is time to change them. I replace mine about once a year, but my tap water is at 120 ppm so they will last longer than yours would.

 

[Steveg229]

From what I have been reading it sounds like with tap water that high a 5 stage rodi will not be able to get it to 0. What do you think I need to add? Another prefilter, or another DI to my exisiting unit?

This makes me want to add a whole house filter for our drinking water...

 

[d2mini]

I would call and talk to the guys at The Filter Guys
See what they suggest.

as far as when to change, i always get zero tds out of the DI but usually by the time the resin changes color things are slowing down and getting clogged so that's when i change the DI and filters. The membranes i change once a year or so.