Tds Readings

[arch]

Hi Folks

Took some readings from RO DI water shortly after filling container.

Result: 0 TDS

48 hrs later I rechecked.

Result: 19 TDS.

Container is cleaned regularly but is not sealed. Kept under sink in cupboard so not exposed to dust, wind etc. Do I need to store in an airtight container, or is it the fact that I`m storing the water that gives the TDS reading time to increase?

Archie

[nickd]

Think of RO as a sponge, by that I mean it can absorb certain things from the air. Just put some in a glass and check later, you will get a reading but not from water test kits.

What is absorbed may not necessarily be harmful, however you are best placing in a sealable container in storing for an amount of time.

Nick

[kim]

I agree with Nick's chemistry, but since I started to clean my containers better, my RO stays within one or two ppm of the original reading over a month or so. Covered, but hardly sealed.

I clean with dilute household bleach, rinse like a maniac, then dry off any remaining water. Smell the freshness.

So long as it's a food safe container, then as Nick also says, it's probably not anything to worry about. If it's in a antique pewter mug, that would be worse !

After all, we don't need close to zero ppm - we just want close to zero of the bad stuff.

kim