Crazy Salinity Numbers! Nervous!

Stlouphil · Nov 20, 2017

Received a New Refractometer and calibration solution today. Got some Crazy Salinity Numbers.

Pinpoint Salinity Monitor:
Calibrated with 35ppt (53ms) solution.
Tank water tests 51ms approximately 1.0252 Tank Water temp 77F

New Refractometer:
Calibrated with 35ppt (53ms) solution.
Tank water tests 45ppt approximately 1.034 Tank Air Temp 68F

Deep Six swing are hydrometer:
Tank water tests 51ms approximately 1.026 Tank Water temp 77F

Any ideas on why things are all over the map?

EriksOasis · Nov 20, 2017

Are you sure both refractometers are calibrated correctly? I found it to be easiest to use Rodi water and set them to zero.

Randy Holmes-Farley · Nov 20, 2017

I'd retest both devices with the Pinpoint fluid and see what you get.

Stlouphil · Nov 21, 2017

I’m going with the refractometer. Calibration fluid was dead on at 35ppt and RO/DI it was spot on at O ppt. Like Randy said I’m going to get the Pinpoint fluid and test again. Everyone seems happy.

Randy Holmes-Farley · Nov 21, 2017

Stlouphil said:
I’m going with the refractometer. Calibration fluid was dead on at 35ppt and RO/DI it was spot on at O ppt. Like Randy said I’m going to get the Pinpoint fluid and test again. Everyone seems happy.

What type of refractometer? Not all "should" read RO/DI as 0 ppt when properly calibrated at 35 ppt.

Stlouphil · Nov 22, 2017

Randy Holmes-Farley said:
What type of refractometer? Not all "should" read RO/DI as 0 ppt when properly calibrated at 35 ppt.

I made my own salinity solution according to your recipe. Refractometer tested 35ppt. Pinpoint was 49ms! Recalibrated the Pinpoint. All is well and everyone seems to be happy. Fingers crossed. Thanks!