2025 Upgraded 4-in-1 Turbidity TDS Meter

Seems to work fine, shows a "better" reading where I would expect it, but note I have nothing to compare it against or calibrate it to....

Good

You can’t give a zero. Got it and would not turn on. Changed batteries still nothing.

This TDS pen is not ideal for any kind of accurate measurement. I have aquariums and the use of a TDS pen is helpful when remineralizing water, where a few TDS can change the chemistry. I have a few other TDS pens that all read within the same range, give or take 1-2 TDS. This TDS tester ranges from 15-25 off these known working, and similar, pens.

This is decent for an approximation, but when comparable value pens are available that are more accurate, there’s no reason to get this. Just pick another $10 option. Interesting enough, this pen advertises a 3% standard deviation, and that is not the case.

I am amazed at what i have been drinking both out of the faucet and older major brand name filter. one tested over 2000. With a smaller culligan zero set up and tester now reads 0 to 2. New unbranded carbon gravity drip filter with new containers also tested 0. I have city water out of the faucet at 724-800.