If your tap water is 701 do not drink it. That would be extreme. And if your tap water is that high then the 146 might be 1460 depending on how the meter reads. Do you have any calibration solution to check the meter with ?

Looking at the info on the meter. Did you see a blinking 10x light ?

Checking the meter is number one. Then you can go from there.

For now I would get some R/O water or distilled water and put in your areo system untill you figure out the meter. Either one should show next to nothing on the meter. If thats the case you got some hella water coming out of that tap.
LOC NAR on probation Reviewed by LOC NAR on probation on . EC-3 reading confusion! Hi, I just took a reading on one of these EC-3: Handheld Conductivity Tester with Case - HM Digital (EC-3 meter) and the reading was 146 - and when I did a reading on my tap water it was 701 ... just wondering if I'm doing this wrong, as it is really confusing for me. The 146 reading is in my aero setup and they are 2 week old seedlings (which look like they arn't doing to well - the 1st true leaves curling under - any help would be really great. Thank you for your help! :) Rating: 5