Salinity Calibration Off...Who To Trust

[Marco S]

I have my refractometer calibrated with the fluid it came with from BRS and my Neptune Apex salinity probe calibrated with the fluid that came with it. My refractometer is reading my salinity at 1.026 or 35 Ppt and Apex is reporting it as 30.4 Ppt.

Which one do I trust???

 

[1Blazer]

Personally the Salinity Probe is very difficult to calibrate in my opinion... I would go with the refractometer and try to get the probe calibrated again--- Keep in mind there is a temp adjustment that can be applied to the Apex probes settings. Just a thought

 

[reacclimating 2 the hobby]

Agreed with the above.

 

[Jeight]

My apex says 29.1 my refrac says 1.025 and I calibrate it everytime with the solution ...I do not trust the apex probe..was considering trying to recalibrate it

 

[Tiger Brown]

Personally the Salinity Probe is very difficult to calibrate in my opinion... I would go with the refractometer and try to get the probe calibrated again--- Keep in mind there is a temp adjustment that can be applied to the Apex probes settings. Just a thought

Definitely a +1 on this. Probes can be touchy to get locked in, but your refractometer should be good to go.

 

[Waters]

As everyone else said, don't trust the probe. I use them strictly to watch for swings as a fail-safe to shut of the ATO or automatic water changers in case there is a problem. Just watch for changes in numbers and use your refractometer to get your actual level.

 

[Marco S]

Wow...so the $35 device is more trustworthy than the $799 one.

Since it seems like a unanimous decision here, I will trust my refractometer and try and re-calibrate the Apex probe.

Thank you for the quick replies everyone!

 

[PatW]

I have the apex probe. I use it to track changes in salinity. I do not trust it absolute measurements.

I would go with the calibrated refractometer.

If you are still in doubt go to your LFS and see what their calibrated refractometer yields.

 

[moz71]

I have same issue right now. For a little piece of mind I simply took to the LFS and they checked with the cheap hydrometer thingy and was close to my milwalkee digital refractometer and probe was way off so now i am just using it for swings and will buy a new probe sometime in future (because my probe may is old) It would be sad if yours is new though.

 

[lapin]

Reefractometer is the best . Salinity probe for changes as mentioned above.
799.00 is a lot for a salinity probe.

 

[Marco S]

I have the apex probe. I use it to track changes in salinity. I do not trust it absolute measurements.

I would go with the calibrated refractometer.

If you are still in doubt go to your LFS and see what their calibrated refractometer yields.

Good call, I will check with my LFS just for a little more piece of mind. Thanks!

Reefractometer is the best . Salinity probe for changes as mentioned above.
799.00 is a lot for a salinity probe.

I meant the Apex Controller was $799. If the salinity probe was $799 I would be so mad that it was not accurate.