FINALLY Calibrated my Neptune Conductivity Probe (Properly)

[scotto]

I, like many others, have had issues with the conductivity probe from Neptune Apex. When I had the Profilux 4, it's probe nicely matched my two Hanna conductivity probes. After switching to the Neptune realm, I never was able to get included probe to calibrate. I purchased another on the off chance of a probe issue, but still had the same problem of incorrect readings (45+ ppt!).

Again, the probe was calibrated according to Neptune's instructions. I also tried BRS's recommendations. I tried some wacky Facebook post recccomendations. No luck. Generally, the probe was fully dry (at least overnight) and the calibration solution was pre-warmed with tank water close to the Apex temp probe.

I failed again, and grabbed my old fully dry probe, and decided to try with the Hanna 35 ppt pouch. I used the manual calibration function to do this, with a TC of 2.1. Amazingly, it is now reading the same as my two Hanna probes. This is critical for me, as it is the Hanna probes which are used to mix up my salt.

Hopefully this helps others who have tried any last ditch efforts to get their probes working.

 

[SPR1968]

I do something similar, I use the Hanna as the bench mark, and when I’m happy the tank water is at 35 when it calls for the solution it goes back into the tank to complete the calibration

Is the only way I can get it to read correctly

If I use the Neptune solution, like you found it’s way out

 

[ShepherdReefer]

Same here, except I used the Milwaukee.

 

[John08007]

Curious, which Hannah checker are you using? I use a specific gravity checker and a refractive one. Sure the Hanna would be a lot more accurate.

 

[MikeTheNewbie]

Did anyone figure out why you got better results with the Hanna calibration solution instead of Neptune's own calibration solution?
I'm experiencing the exact same situation. Wasted several Neptune satchels until I decided to try the Hanna ones.
That solved my problem but it doesn't make any sense to me. Am I doing something wrong?

 

[Butcher333]

I’ve spent days fiddle farting around with this thing. It simply doesn’t work. When I originally hooked it up I had missed the step about temp compensation, so I had just assumed the fluctuations were related to this. I got tired of the fluctuations and decided to calibrate it by adding a number greater than 0 (2.2) so I could have stable salinity. I’ve been dosing for a few months now and want to know when my salinity is getting high so I can adjust it out. I randomly checked it with my refractometer and was always fine. 1.025ish./34/35ppt.
I’ve literally read and done it all. I have a scale that measures to the hundredths place. I used the formulas by Randy Holmes Farley. 1st the Morton salt version for conductivity. Each time I calibrated I got a different number. Reset apex. Calibrate unplugged. Recalibrated. First it started off reading perfect in the solution but would jump to 45-49. Checked for stray voltage. Tested in a cup of water outside of tank. Then I finally got it to give good readings until I placed it back in tank. Always reading 30.1 through 30.9.
today I decided I would try the solution using KCl and both test off still. 32.8 in calibration fluid and then drop to the old 30.1 to 30.9. I’ve recalibrated my refractometer 8 times. Always reads dead on. 35ppt/1.025ish. So to settle the matter I went and dug out my old hydrometer and it reads 1.0255. So I think it’s pretty safe to say that a conductivity probe is not very accurate. Lame. I’ve waisted enough emotional resources on this problem. I can only imagine that some sort of ionic imbalance it causing the issue that doesn’t affect a refractometer or a hydrometer. The same way that the the solution used to calibrate a refractometer will give different readings than that used to calibrate a conductivity probe etc. etc.
if adding magnesium chloride and calcium chloride change anything, I’ll post this update.
thank god for old reliable methods.

 

[Clownfishy]

I do something similar, I use the Hanna as the bench mark, and when I’m happy the tank water is at 35 when it calls for the solution it goes back into the tank to complete the calibration

Is the only way I can get it to read correctly

If I use the Neptune solution, like you found it’s way out

I do exactly the same and this works perfectly. The only time it drifts is if one of the many tiny star fish I have in my aquarium crawl inside the probe and then the reading jumps all over the place until the star fish leaves!

 

[SigmaVX]

Sounds like interference with electrical wiring and bubbles can play a role. I re ran my control wires and did calibration in water I tested at 35 with refractometer. It be move around a little but not much. I also noticed it moves with temp.

 

[FisheRare]

I do something similar, I use the Hanna as the bench mark, and when I’m happy the tank water is at 35 when it calls for the solution it goes back into the tank to complete the calibration

Is the only way I can get it to read correctly

If I use the Neptune solution, like you found it’s way out

Do you do manual calibration dry probe ,then use the hanna 35 solution as the 53,000 neptune soulution then add back to tank?

 

[FisheRare]

Did anyone figure out why you got better results with the Hanna calibration solution instead of Neptune's own calibration solution?
I'm experiencing the exact same situation. Wasted several Neptune satchels until I decided to try the Hanna ones.
That solved my problem but it doesn't make any sense to me. Am I doing something wrong?

So instead of using the neptune solution you used the hanna solution instead and then add back to tank?

 

[CBonito]

Weird, mine is dead accurate against my refractometer and I used the neptune stuff.
Only problems I've ever had was when the probe was new, I had to shake it every day to get it to read accurately again. That has since stopped.