APEX salinity probe keeps climbing - do I need to re-calibrate?

[BanjoBandito]

So I've been running the apex for about 2 weeks and my salinity readings were fine. Yesterday it started throwing alarms at me for salinity over 38 ppt. I double checked it vs. my Milwaukee refractometer and a hand held thingy. Both read at 1.025-1.026. Has anyone any insight on to what is going on with the probe? Does it need re-calibrated? I use it for "TRENDS" not accuracy. But nothing has really changed in the tank to cause the spike at the probe. I have it grouped with the other probes in my sump in a holder....I know there's some "break in time" for these probes, but I've also read there can be interference from other equipment. Just kinda looking for some insight as to what is going on. It would be nice to be able to TRUST the trends of the probe readings?

 

[dank reefer]

Make sure that there are no bubbles in the probe opening. I usually vigorously shake the probe underwater to release any trapped bubbles.

But Honestly... there salinity probe sucks!

 

[BanjoBandito]

Make sure that there are no bubbles in the probe opening. I usually vigorously shake the probe underwater to release any trapped bubbles.

But Honestly... there salinity probe sucks!

Yeah, I knew that going into it but I felt I could use it for "trends" and another layer of protection. I will check the bubbles. Does it make sense to install a small pump in my sump to keep modest waterflow past the probes?

 

[brmc1985]

If it’s not reading correctly it’s time to make sure there are no bubbles in it. Do what the person above said and shake it. See if it reads correctly. Move it to another area of the sump with no bubbles. If it still reads incorrect, clean it and calibrate it. If that doesn’t work contact Neptune and you might get a new one. Or just get another one and run with that.

 

[BanjoBandito]

Would adding something like this make a difference?

https://www.bulkreefsupply.com/sali...lzZE2_uWw8POGolNB_sURv6eOy-rvjFwaAj3wEALw_wcB

 

[brmc1985]

Yeah, I knew that going into it but I felt I could use it for "trends" and another layer of protection. I will check the bubbles. Does it make sense to install a small pump in my sump to keep modest waterflow past the probes?

https://www.bulkreefsupply.com/sali...L76Dhn_k1-33GHY7nvixRBI70MTxxWbQaAvyxEALw_wcB

 

[brmc1985]

Would adding something like this make a difference?

https://www.bulkreefsupply.com/sali...lzZE2_uWw8POGolNB_sURv6eOy-rvjFwaAj3wEALw_wcB

You beat me to it. Yep. This would be your best bet. Might not help this probe but would help with a replacement. Also, I think you are supposed to let the probes be in the water for a couple weeks and then calibrate. Give it a shot!

 

[wazzupmac]

I calibrated with the Hanna 35ppt solution recently and my probe has been spot on since I did that. I had similar issues to the OP and read something about the Hanna solution fix and it’s been great. I have moved no more than .2 with the ATO working, etc.

 

[brmc1985]

Would adding something like this make a difference?

https://www.bulkreefsupply.com/sali...lzZE2_uWw8POGolNB_sURv6eOy-rvjFwaAj3wEALw_wcB

Also, check your temperate. Increase in temp can cause the probe to read high as well. Be sure to let the calibration solution come to temp in the tank water too!!!!

 

[BanjoBandito]

You beat me to it. Yep. This would be your best bet. Might not help this probe but would help with a replacement. Also, I think you are supposed to let the probes be in the water for a couple weeks and then calibrate. Give it a shot!

I might pull the trigger on this, but I think I'll wait a few weeks then re-calibrate like someone else suggested. I'm still getting to know this Apex system. I have trust issues. lol.

 

[brmc1985]

I might pull the trigger on this, but I think I'll wait a few weeks then re-calibrate like someone else suggested. I'm still getting to know this Apex system. I have trust issues.

You should be able to calibrate now. Just double check temperature of the tank. Let the 7 and 10 solutions sit in the tank for 10 minutes before calibrating. Rinse with rodi water between tests. Make sure there are no bubbles and don’t let it be in open air for too long.

 

[brmc1985]

Here’s an example of how temp affects salinity.

 

[Randy Holmes-Farley Verified Community Expert]

Temperature should only impact reported salinity if your conductivity meter is not properly correcting for temperature changes.

Salinity, of course, does not change with temperature.

 

[brmc1985]

Temperature should only impact reported salinity if your conductivity meter is not properly correcting for temperature changes.

Salinity, of course, does not change with temperature.

Guess I will have to take a look at that in Fusion then! Thanks Randy!

 

[Sean Clark]

Check out this thread. This worked wonders for my salinity probe stability.

https://www.reef2reef.com/threads/a...ex-salinity-calibration-and-tc-factor.718971/

 

[BanjoBandito]

Temperature should only impact reported salinity if your conductivity meter is not properly correcting for temperature changes.

Salinity, of course, does not change with temperature.

Randy, so are you saying that the apex probe is already correcting for that? Do you think re-calibration is the issue here? Would a setup I posted improve it at all? Does that make sense? Give it flow and avoid bubbles/debris?

 

[BanjoBandito]

Check out this thread. This worked wonders for my salinity probe stability.

https://www.reef2reef.com/threads/a...ex-salinity-calibration-and-tc-factor.718971/

I will dig into this after my scuba dive tonight. Thank you!

 

[brmc1985]

I will dig into this after my scuba dive tonight. Thank you!

This will answer your question from above about the correction. I just took a look at it and it's one of the first things in the article. Whoever wrote that needs a beer bought for them.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, so are you saying that the apex probe is already correcting for that? Do you think re-calibration is the issue here? Would a setup I posted improve it at all? Does that make sense? Give it flow and avoid bubbles/debris?

My understanding is that some controllers allow the user to adjust or turn off the correction, but anything that purports to provide the salinity of seawater by conductivity must make that correction.

Another problem is that most conductivity meters have the temp sensor built into them. If a controller measures temp elsewhere with a different probe that might read differently during, say, calibration, that’s a big problem if the temp is different.

 

[BanjoBandito]

This will answer your question from above about the correction. I just took a look at it and it's one of the first things in the article. Whoever wrote that needs a beer bought for them.

Yeah a brief skim seems like I need to re-calibrate it. I guess what I'm not clear on is setting the TC value before or after the new calibration.