[JandS]

When the batteries go on them do they just die or start giving erratic readings.
Reading from first Di was around 15 last week before hitting second Di, today it was 4....after second Di with week old resin it was 1/2.

[andyM]

You should try calibrating your TDS meter first (ideally using calibration fluid) if you haven't done already.

[dazmond]

You should try calibrating your TDS meter first (ideally using calibration fluid) if you haven't done already.

how do you calibrate a tds meter? and where do you buy calibration fluid from?

i just usually buy another one if changing batteries doesnt fix it.their cheap enough.

[JandS]

+1??

[richard groves]

I've no idea if its possible for them to give a false reading because of low battery ( but I doubt it ) . I recently changed batteries in an inline one because the LCD display was very weak and you had to look at it at a certain angle to read it ...... it did however show the true reading when compared to my handheld one.

[JandS]

This makes it clear.

https://www.theaquariumsolution.com/calibrating-tds-3-hand-held-tds-meter