Conduvtivity probe calibration frustrations

[Reefinmike]

Hey all, I’m not sure if everyone else is experiencing these frustrations with their apex salinity probe. The probe would have been the one silver lining to the fact the Apex EL came out literally the day I got my full version for $300 more. These calibration solution packets aren’t cheap and I have used five of these already with only 4 weeks of satisfactory monitoring. From everything I’ve read it is imperative to purge all air when calibrating. Someone on youtube had a good idea of using a probe tip liquid vial and completely inverting /shaking the probe. Three of the 5 calibrations started showing the tank at 32.5ish and rose to 100 over a handful of days. $12 down the drain. One was successful and remained relatively steady for a month until I unplugged the probe for 10 seconds. The last calibration at step 4 I inserted the probe, inverted and shook out all the air as fast as i could. The reading settled before i was confident i removed all the air. Less than 15 seconds after hitti g next on step 3.

Am I supposed to insert the probe on step three while choosing the calibration solution? Is it normal for the probe to lose calibration when unplugged for a few seconds? I’m tired of sending money down the drain. I’ve done everything possible, isolating the wire far from any other electronics, calibrating exactly as instructed, turning all ballasts or nonessential nearby equipment off.

 

[Muttley000]

Here are a few things that helped me get my second one right the first time

I let the probe sit in my tank for a week before trying to calibrate
I isolated its cable from any other equipment wires
I floated my solution bag in the sump for an hour
I only cut the corner of the bag so it stayed as warm as possible during the calibration
I blew the tank water off the probe with canned air (like you use in a computer) when I calibrated

I hope one of these help!

 

[Reefinmike]

You let the probe sit in your tank for a week before calibrating? I’ve always read the probe should be washed in ro/di and dried for a day before calibrating.

 

[Muttley000]

You let the probe sit in your tank for a week before calibrating? I’ve always read the probe should be washed in ro/di and dried for a day before calibrating.

Yes I did hooked to the apex, and I observed the value moving more than my salinity could have possibly been moving before it settled down

 

[User]

Yes I did hooked to the apex, and I observed the value moving more than my salinity could have possibly been moving before it settled down

What he’s saying is that step 1 of the calibration is to fully dry the probe.

Did you do this after letting it sit in your tank for a week? Or just pass the drying step and go to step 2?

 

[vhuang168]

After you finish the calibration, leave the probe in the solution and go to the dashboard. Wait about 2-5 minutes and see what the probe reads in the calibration solution.

If it reads close to 35, then it is calibrated.

 

[mborn]

Is that the auto calibration? Try the manual calibration mode, that worked well for me. It's in the advanced tab.

 

[Reefinmike]

Is that the auto calibration? Try the manual calibration mode, that worked well for me. It's in the advanced tab.

Thanks for the suggestion. I’ll have to try out the manual calibration. The first two calibrations were done on the apex display and the other three through fusion. Hopefully this manual calibration gives me more than 10 seconds to put the probe in solution.

I’ll also leave it in the solution to see what it reads after calibrating.

 

[Reefinmike]

Ok so i just recalibrated for the 6th time; this time using the manual probe calibration in fusion. The temp compensation was at 0.0 by default so i set it to the 2.2 neptune recommends. I didn’t see any option to pick a temp probe. I have two probes on my 90.

I did everything by the books. Bone dry probe, calibration solution floated in the sump, wire isolated and turned off every piece of equipment aside from my return. I left the probe in the solution after calibration. The salinity started at 40 and quickly settled to 30.8. The probe reads my tank water at 44.3ppt.

Another $4 down the drain. This is so unbelievably frustrating. I’ll pull the probe out , rinse in ro/di and dry if I don’t see any change in a few hours. I’ll recalibrate tomorrow with neptune on the phone

 

[Muttley000]

What he’s saying is that step 1 of the calibration is to fully dry the probe.

Did you do this after letting it sit in your tank for a week? Or just pass the drying step and go to step 2?

I dried it after letting it sit in the sump