Repiped house, TDS lowered?

cope413 · Jan 26, 2016

Just finished an incredibly fun 7 day repiping at our house. Ripped out the copper and installed PEX.
Drywall dust and paint fumes are is good for reef tanks, right?

Anyhow, I got my RODI system reinstalled and my TDS dropped from 440-470 to 370-375.

Our copper piping wasn't even 20 years old, and we didn't have any plumbing issues (long story, but entire community was forced to repipe by HOA due to some shoddy construction)

Does that drop make sense from the change in plumbing or is it just a coincidence?

Triggreef · Jan 26, 2016

I have very old copper plumbing in my house. Like 40 years old. My tds with well water is about 93 to 103 before ro, so I can not as that drop coming from changing the plumbing. Although maybe some filters are changed as well? Carbon filters?

Randy Holmes-Farley · Jan 26, 2016

I don't see a reasonable explanation for the TDS drop based on swapping out copper for PEX. There's no reasonable chance there was 50-100 ppm of copper (or other metal) dissolving into the water before the change.

cope413 · Jan 26, 2016

That's what I thought, too. Strange. I check my In/Out TDS weekly, and I had never seen it below 400. Hooked it up after the repipe and suddenly 370ish.

Chalk it up to coincidence for now I suppose.