Neptune Salinity Probe issues

[ZoWhat]

I just added a Salinity Probe to my sump. I've followed the Apex setup step by step.

* I'm starting the calibration with probe completely dry
* I'm using the 53000 solution
* I'm using the Apex temp probe and the solution is the same temp
* the calibration is testing 35.1 in solution
* the probe cable is isolation from any Interference

Problem is it reads 31.5 in my sump water when water is 1.025 after cross checking with calibrated refractometer

I know my skimmer pump leaks a little voltage (how much, idk)

Problem.is this skimmer pump works great and it's $300 to replace. Not doing that over a very small voltage leak.

1) is a little voltage throwing a reading of 31.5 in 1.025 water?

2) any way to mitigate this voltage? I've tried a titanium grounding cable via BRS but doesn't mitigate the voltage



.

 

[gbroadbridge]

I just added a Salinity Probe to my sump. I've followed the Apex setup step by step.

* I'm starting the calibration with probe completely dry
* I'm using the 53000 solution
* I'm using the Apex temp probe and the solution is the same temp
* the calibration is testing 35.1 in solution
* the probe cable is isolation from any Interference

Problem is it reads 31.5 in my sump water when water is 1.025 after cross checking with calibrated refractometer

I know my skimmer pump leaks a little voltage (how much, idk)

Problem.is this skimmer pump works great and it's $300 to replace. Not doing that over a very small voltage leak.

1) is a little voltage throwing a reading of 31.5 in 1.025 water?

2) any way to mitigate this voltage? I've tried a titanium grounding cable via BRS but doesn't mitigate the voltage



.

Leakage voltage can disturb the measurement.

Also, use a different calibration solution as the supplied ones are not always accurate.

It is trivial to make your own DIY calibration solution as shown in this article.

https://reefkeeping.com/issues/2004-06/rhf/index.php

 

[Mark Goode]

I think they're a pain in the backside. The readings seem to depend on whereabouts in the sump the probe is placed. Give the thing a wiggle about in the water and try different places in the sump until it gives a reading that isn't stupid, and use it just to see any trends. I wouldn't trust mine further than that.

 

[gbroadbridge]

I think they're a pain in the backside. The readings seem to depend on whereabouts in the sump the probe is placed. Give the thing a wiggle about in the water and try different places in the sump until it gives a reading that isn't stupid, and use it just to see any trends. I wouldn't trust mine further than that.

Like any precision scientific instrument they're fussy and not forgiving of error.

Salinity probes are definately not a drop in the sump and expect a perfect reading type of measurement device. Air bubbles can make them unreliable and can flow problems in the sump.

 

[Addicted2ACRO's]

Has anyone had any of the calibration fluid spill into the sump while performing calibration? I had a little fall into my sump. Are their damaging results?

 

[gbroadbridge]

Has anyone had any of the calibration fluid spill into the sump while performing calibration? I had a little fall into my sump. Are their damaging results?

It's potassium chloride which is harmless.

I dose potassium chloride solution to maintain potassium levels.