RODI problem? I'm stumped.

[camens]

I installed my RODI system and am using it for ATO water and mixing salt water. Its for a 13.5 Fluval Evo so its pretty small. However, I'm concerned about the readings. The TDS meter shows 0 ppm inline, but when I use my handheld meter its showing anywhere from 3 - 7 ppm. The number sometimes moves while I'm holding the handheld tester in the water? Do I assume my water is OK and I have a faulty hand held tester? Its a brand new setup but I guess it could be one of the filters? Kinda stumped and nervous about adding this water to the tank. I have 2 testers already and hate buying a 3rd, but maybe thats the answer?

 

[Justdrew]

Put the water directly in a clean glass to use the handheld. Measuring in a plastic container will always be higher as the plastic will leach. Even my food grade brutes will cause higher TDS readings.

 

[camens]

I'll give that a try. Is that OK though? Are we then not defeating the purpose of the RODI? My containers are food grade so I thought they were safe.

 

[SPR1968]

I would trust the inline one because if you test in a glass or container in my have some form of minor contamination in it, and yes your fine with plastic storage containers.

If I test the RODI in my plastic container of 425 litres, that sometimes reads above zero for whatever reason with the hand held.

 

[Malcontent]

One or both could be out of calibration.

 

[mann1139]

I just bought a new inline and it said when testing static water to correct by a couple TDS. Forgot which way.