New to Apex

[Dedicated Reefer]

I’m wondering if my salinity probe can mrs pre calibrated. I have three separate salinity testers and they all read 35 ppt and the apex is reading 28. How can I correct this. Thank for helping out!

 

[ColoredRock]

need to calibrate it.. do a search on the forums... Salinity probes can be a finiky PITA

 

[CoralFarm]

I’m wondering if my salinity probe can mrs pre calibrated. I have three separate salinity testers and they all read 35 ppt and the apex is reading 28. How can I correct this. Thank for helping out!

As @ColoredRock said, they're finicky as heck and a pain in the butt. If the calibration is off, you can go into the settings in Apex to adjust how off it is. In my experience, they need to be recalibrated at least every other week to be somewhat reliable. Something to keep in mind is that as long as your water level stays the same, your salinity will as well since it doesn't evaporate.

In my sumps, I have a little piece of tape where the water needs to be at my return pump. I just use RODI water to top it off. As long as it stays at that spot, I know my salinity will be where I need it to be.

If you do water changes, mix a batch of water up so that you only have to test it once when you first mix it. Make sure you keep a tight-fitting lid on it for when you're not using it so evaporation doesn't take place.

 

[DivingTheWorld]

I’ve had an Apex salinity probe for about a decade (swapped it out once after a couple years) and I’ve got it to register correctly for about 1 month in that time. It just sits in my sump and does nothing. Some people can get them to work right, but it seems like most can’t from what I’ve read.

Hopefully you’ll be in the former category.

 

[CoralFarm]

I’ve had an Apex salinity probe for about a decade (swapped it out once after a couple years) and I’ve got it to register correctly for about 1 month in that time. It just sits in my sump and does nothing. Some people can get them to work right, but it seems like most can’t from what I’ve read.

Hopefully you’ll be in the former category.

That's also why I believe the newer Apex systems don't even come with it anymore.

I can still see the use of it if it was reliable, but it's just easier to use and calibrate the cheap manual tools since it's only really important when mixing new batches of saltwater up.

 

[Sisterlimonpot]

If the calibration is off, you can go into the settings in Apex to adjust how off it is.

Can you explain this? How do you adjust the conductivity probe?

 

[ColoredRock]

Can you explain this? How do you adjust the conductivity probe?

take a fun read thru this thread if you havent....

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

 

[CoralFarm]

take a fun read thru this thread if you havent....

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

Thank you. I couldn't for the life of me remember what the offset was called (Temp Calibration) and my phone is being weird about logging into Apex right now. It's the only way I've been able to get it to work at least somewhat reliably.

 

[Sisterlimonpot]

take a fun read thru this thread if you havent....

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

That doesn't say anything about being able to make adjustments to correct for wrong salinity, that's just explaining how fusion software uses temperature to make the readings from the conductivity probe more accurate and how the user can alter TC to tighten the sine wave.

I took it as, he was suggesting that you can correct the reading by manually adjusting how off it is.

 

[ColoredRock]

I took it as, he was suggesting that you can correct the reading by manually adjusting how off it is.

I read it as you can correct the variance thru messing with the TC factor. But i can see how it could be read the other way as well.

 

[Sisterlimonpot]

I read it as you can correct the variance thru messing with the TC factor. But i can see how it could be read the other way as well.

I guess we can claim ambiguity.

The original poster asked how to correct 28ppt when others testers read 35ppt.

Although, knowing how TC effects accuracy is good to know. I think this is a case of recalibrating the probe and perhaps go down that rabbit hole if calibration doesn't solve the issue.

I don't think that recallibrating every few weeks is good advice either, if you're doing that then, I'd suspect a faulty probe.

One thing that's worth mentioning here is that the way these probes are designed, they tend to trap air bubbles and every once in a while when my salinity doesn't look right, I wiggle the probe and release any trapped air, and it starts reading properly again.

 

[buruskeee]

What I do is, once calibrated properly, I swirl my probe around in the sump and tap it underwater against the glass to make all air bubbles vacate the probe area. Also, it takes time to update, it’s not instant - so either set your apex update every minute for half an hour, or wait it out and it’ll slowly come up to the levels it should be at, assuming the probe works correctly.

 

[CoralFarm]

I guess we can claim ambiguity.

The original poster asked how to correct 28ppt when others testers read 35ppt.

Although, knowing how TC effects accuracy is good to know. I think this is a case of recalibrating the probe and perhaps go down that rabbit hole if calibration doesn't solve the issue.

I don't think that recallibrating every few weeks is good advice either, if you're doing that then, I'd suspect a faulty probe.

One thing that's worth mentioning here is that the way these probes are designed, they tend to trap air bubbles and every once in a while when my salinity doesn't look right, I wiggle the probe and release any trapped air, and it starts reading properly again.

It's effectively an offset with a different label. As long as your temperatures don't shift much, the offset will be as accurate as the probe can read. We have 10 different apex systems at our farm and this is a consistent issue across all of them.

 

[ColoredRock]

I guess we can claim ambiguity.

The original poster asked how to correct 28ppt when others testers read 35ppt.

Although, knowing how TC effects accuracy is good to know. I think this is a case of recalibrating the probe and perhaps go down that rabbit hole if calibration doesn't solve the issue.

I don't think that recallibrating every few weeks is good advice either, if you're doing that then, I'd suspect a faulty probe.

One thing that's worth mentioning here is that the way these probes are designed, they tend to trap air bubbles and every once in a while when my salinity doesn't look right, I wiggle the probe and release any trapped air, and it starts reading properly again.

If you read thru that thread there are other people that had the same issue. No ambiguity at all on my part.

 

[Sisterlimonpot]

It's effectively an offset with a different label. As long as your temperatures don't shift much, the offset will be as accurate as the probe can read. We have 10 different apex systems at our farm and this is a consistent issue across all of them.

Wait a minute, now your saying you DO use TC to alter the reading?

Back to my 1st post, can you explain how you do that?

If you read thru that thread there are other people that had the same issue. No ambiguity at all on my part.

I'm having a hard time following, are you saying that there are accounts in that thread that people are using TC to change the calibrated point of their conductivity probe reading? I read through 4 pages of that thread and haven't come across someone saying they used TC factor to correct a wrong reading.

He even said in his post (mind you after you posting the other thread) that he called TC a "calibration" not a 'compensation"

I couldn't for the life of me remember what the offset was called (Temp Calibration)

It appears we are on the same page, and understand what TC does. What I'd like to know, and I doubt will get an answer is the procedure to use TC factor to correct a probe that isn't calibrated correctly.

 

[areefer01]

Wait a minute, now your saying you DO use TC to alter the reading?

Back to my 1st post, can you explain how you do that?

I read, and interpreted, it the same was as you not that it matters.