TDS vs. hardness

Just curious: My customer yesterday had a TDS of 237, which is high for my area. They are on their own well and they have a water softener going for the whole house. I tested the water for hardness ( I have a kit that I use for my own home) and it came out at 2 (grains?)…in other words it was soft. The PH was 8. Is the TDS “high” because of the added salt? Is there a correlation between hardness and TDS?

Where are you located in NC?

Located in the Charlotte area.

… There is some correlation but not much. That is, soft water helps a tad. Go by your TDS. Well water I find almost always has has a higher tds than city water. Also on many homes with “whole house” soft water, it does not include outside spigots.

Just test mine. Unsoftened 523, softened 533.

Just read online that softeners don’t remove TDS, they exchange them. That is…a softener will exchange calcium and magnesium (hard dissolved solids) with sodium (a soft dissolved solid).

Right! A water softener will never reduce the TDS. Calcium will scale, Sodium does not, so in high calcium hardness, any system can benefit from a softener if it is unable to be flushed or drained, and particularly if there is hot water involved.

There is no ‘golden rule’ to water and spotting which is why the gravitation to TDS 000 - but you can test your local water to see what spots you are dealing with when you are purifying the water.

Cool…thanks guys…that makes sense!