Easy way to calibrate salinity probe

Cabinetman · Sep 21, 2020

So I know I’m not the only one to have trouble with the salinity probe. Last night I tried something and it seams to have worked perfect and was fast and easy. I know my tank is right at about 35 so what I did was start the calibration process and when it said dry the probe I instead swirled it good in Rodi water and then let it stay in the Rodi water till it was Time to do the next step. Picked the 5300 choice then put the probe in my sump making sure to get all the bubbles out and put it exactly where it’s going to go. I then started the last process and once it settled and calibrated it seams to be holding. Salt has measured 35.1 ever since. Not sure how everyone else gets these probes to work but using the calibration fluid I always found it screwed up when I put it in my sump..or moved it, or looked at it lol.

AcanthurusRex · Sep 21, 2020

I just calibrated in the sump. The SG measured 35 and I wanted the probe to read the same.
The trick to this probe is to make sure there are no bubbles in the area the probe is mounted. Any bubbles will cause the readings to drift.
The probes seem prone to fail and are expensive. Mine has failed for the second time and I have chosen to not use it.

Cabinetman · Sep 21, 2020

You’re right. The spot it’s placed has to be free of micro bubbles, and you also have to make sure there’s no air bubbles in the end of the probe when you do the final calibration in the sump. If there is and that bubble cones out it will throw the reading off. I layed mine on it’s side right at the bottom of a baffle and made sure there was absolutely no air left in the probe then hit calibrate for the 5300. Then the big thing is to leave it in the same spot and don’t lift it out of the water. It laying sideways on the bottom of the baffle should keep any air bubbles from getting into the end of the probe and throwing it off. Mine is Still holding right on 35..