ARCHER LIFE HALLTDS Meter Digital Water Quality Tester for RO-RODI System Drinking Water, Aquariums, Hydroponics, 0-999 ppm Measuring Range, 1 ppm Increments, 2% Readout Accuracy（White）

It works

I've started to learn how to service my own in-home reverse osmosis water system, as the company that used to do it was charging increasingly large amounts of money for something that really couldn't be that difficult.The only way to know, though, whether the $100+ membrane needed to be replaced was to measure the TDS (total dissolved solids) of the RO water vs our tap water.This is a simple and basically foolproof tool to accomplish that. It works quickly and gives you clear, unambiguous readings. It just saved me over $100 this time out. And I'll know for sure when I actually DO need to spend that on a new part. I'm very happy with it.

Excellent delivery& quality

Tested spring bottle water ppm 496, city water ppm 150, RO water ppm 4, Alkaline water ppm 10. Works as expected.

It’s very accurate easy to use quality is great and value for money is perfect you can read the display easily and it performs every time