Help with Apex salinity probe

[Beazy]

Not sure if I got the right section but I was hoping to see if I could get help with my apex probe. My probe was working somewhat fine and had consistently 2ish ppt higher than my Hannah salinity checked and tropic Marin hydrometer. I went to do a recalibration two nights ago and the end result is that now my probe is 4 ppt (38) higher than both of my other instruments.

Thinking I messed up, I did another recalibration. I did it the same way but slower. Float the solution near the temp probe for 30 min, Take the salinity prob out, rodi rinse, Pat it dry with a new microfiber cloth, gave it a few shakes to get any air bubbles out.

After the calibration I did notice that the prob was reading 40 ppt in the solution. After about a few hours the salinity settled to 38 ppt again.

Wondering if I these calibrations broke my probe, if I may have calibrated wrong or if I should just shift my alarms to center around the new readings and cross check with my other two tools occasionally

 

[bushdoc]

I don't know answer to your questions, but I will watch this thread as I have the same issue.Perhaps somebody knows the answer. I stopped trusting Apex Conductivity probe and check salinity weekly with Hanna checker. I only look at a trend of Apex probe.
My Apex probe shows today 38.5 ppt and Hanna 36.1ppt and so my refractometer.

 

[Beazy]

I don't know answer to your questions, but I will watch this thread as I have the same issue.Perhaps somebody knows the answer. I stopped trusting Apex Conductivity probe and check salinity weekly with Hanna checker. I only look at a trend of Apex probe.
My Apex probe shows today 38.5 ppt and Hanna 36.1ppt and so my refractometer.

This is what I’m going to start doing. Even before the calibration fiasco, I was showing 35 PPT on the apex and 33/32 on Hannah and TM. Trusted the apex over those 2 and now that seems unwise.

 

[blaxsun]

When I've calibrated mine - it typically comes in higher (38ppt) before "settling". There's a process of turning the probe off, unplugging, rebooting the Apex, plugging back in, re-enabling and then re-calibrating that has worked for me (something Neptune suggested).

 

[Beazy]

When I've calibrated mine - it typically comes in higher (38ppt) before "settling". There's a process of turning the probe off, unplugging, rebooting the Apex, plugging back in, re-enabling and then re-calibrating that has worked for me (something Neptune suggested).

I ran out of calibration fluid after last night. This sounds promising, will give this a try the next time I go to my LFS or make a BRS order

 

[All_talk]

This might be helpful...

(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...

www.reef2reef.com

 

[Beazy]

This might be helpful...

(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...

www.reef2reef.com

This is definitely useful. Sadly this is how I calibrated it. Prior to this last round that guide has given me the most stable calibrations ever. Fluctuations were +/- .1

 

[bryan3536]

Same issue, same everything. I’m reading a solid two points over my two calibrated refractometers and it’s driving me a bit nuts. Followed that article to a tee also.

 

[Beazy]

Same issue, same everything. I’m reading a solid two points over my two calibrated refractometers and it’s driving me a bit nuts. Followed that article to a tee also.

Idk if this works for you but I’m using my hydrometer every few weeks to get a real reading and setting my alarms to be relative. That 38.8 I’m reading is 33.8 on my hydrometer so now I’m just basing that 40 as 35ppt until I decide to recalibrate in a few months

 

[V A R I A N T]

Mine reads a consistent 46 with the VCA SPS thingy. Which, I don’t really care so much in the number. The consistency is important, so if it drifts high or low, then I know I have ATO issues. I remember mine reading 35ppt for about 2 weeks. Never got it dialed in to that number again.

 

[Biologic]

Guys guys.

Listen.

My yearly post of this — try not to stress too much about the Apex salinity probe. Your goal should be getting it to be repeatable. My probe was put in recently with zero calibration and it happen to land on 36.3 ppt. Guess what my salinity is? 35.5 ppt via my calibrated high precision refractometer, which was $100 from a science supply website.

which one would I trust more to tell me EXACTLY what the salinity is? Duh. My refractormeter.

however, in the case I am not home and I see my salinity suddenly drop 4 or 5 ppt over a couple hours. Something MIGHT be wrong. I can turn off my ATO and investigate when I get home.

don’t get hung up on the EXACT ppt reading of the reef tank. It’s for emergencies and quick glances day to day.

>>>You should spend more effort on calibrating a quality refractormeter <<<

 

[Beazy]

Mine reads a consistent 46 with the VCA SPS thingy. Which, I don’t really care so much in the number. The consistency is important, so if it drifts high or low, then I know I have ATO issues. I remember mine reading 35ppt for about 2 weeks. Never got it dialed in to that number again.

That’s a bummer. I read that some people have tried completely removing the probe, restarting the apex, then adding the probe back and recalibrating. I was gonna give that shot next

 

[Jason Scalise]

Yes the conductivity probes (aka salinity probes) can be finicky.

Make sure you have it soaked in the salt water for at least a few hours.

Make sure there are no bubbles in the probe. Hard to do when you input it in the water but you can achieve by 1) turning it upside down under water and gently tapping it to let the air bubbles escape and/or 2) use a syringe or turkey baster to blast water into the hole on the side of the probe while it is submerged.
Removing the trapped air helps ensure the conductivity reading is not contaminated.

Lastly, I found it helpful to calibrate it differently. Apex experts may disagree but I used my Milwaukee salinity checker to get a reading. Then I do manual calibration of the probe and use that reading to set/calibrate the probe. This avoids using calibration liquid and it seems to work very well and consistently matches my Milwaukee even months later.

Hope that helps.

 

[Beazy]

Guys guys.

Listen.

My yearly post of this — try not to stress too much about the Apex salinity probe. Your goal should be getting it to be repeatable. My probe was put in recently with zero calibration and it happen to land on 36.3 ppt. Guess what my salinity is? 35.5 ppt via my calibrated high precision refractometer, which was $100 from a science supply website.

which one would I trust more to tell me EXACTLY what the salinity is? Duh. My refractormeter.

however, in the case I am not home and I see my salinity suddenly drop 4 or 5 ppt over a couple hours. Something MIGHT be wrong. I can turn off my ATO and investigate when I get home.

don’t get hung up on the EXACT ppt reading of the reef tank. It’s for emergencies and quick glances day to day.

>>>You should spend more effort on calibrating a quality refractormeter <<<

Knowing what I know now I agree with you. I thought my tank was sitting at 35 ppt this whole time. Just a bummer to pay $200 for a probe that doesn’t work. I’m glad the new apex’s give you the option to opt out and add later

 

[Biologic]

This is what I’m going to start doing. Even before the calibration fiasco, I was showing 35 PPT on the apex and 33/32 on Hannah and TM. Trusted the apex over those 2 and now that seems unwise.

also a good parable — “man who has two wrist watches with different times doesn’t know the time.”

I would use the Hanna in lieu of a good refractormeter. You don’t want a probe that sits in saltwater all day to tell you the exact salinity. Think of the Apex probe as a sun dial and the Hanna a reliable wrist watch. Choose one and stick with it. Test your local LFS’s reef tank or another successful reef tank to see how their water lines up with the Hanna.

 

[Biologic]

Knowing what I know now I agree with you. I thought my tank was sitting at 35 ppt this whole time. Just a bummer to pay $200 for a probe that doesn’t work. I’m glad the new apex’s give you the option to opt out and add later

It does work, your expectations are set too high. This is a consumer level product. Precision AND accuracy are not cheap. Plus it’s in a biological chemical soup with things trying to make their home on it. The pH probe you have? Two digits accuracy is questionable in a reef tank. So many variables. It’s a guide. A safety net. Do not rely on it.

It’s nice to look on my phone and see my salinity at what I left it at, but it also scares the **** out of you when it drops 2 ppt randomly and it’s back up 5 minutes later. But again, it’s a guide. It means nothing without context. The context is time or something I know going on.

the 2016 Apex EL had the optional salinity probe, you’d just have to purchase a PM2 and a probe.

 

[Biologic]

Knowing what I know now I agree with you. I thought my tank was sitting at 35 ppt this whole time. Just a bummer to pay $200 for a probe that doesn’t work. I’m glad the new apex’s give you the option to opt out and add later

Look here’s it working. See this example —

My 1 year old was playing with my refractormeter (really made my stomach turn). Got it out of his hands quickly. Later that day, I made up some saltwater. Changed over a 20 gallons over a couple days. Well look at my salinity graph. Notice something?!?

My salinity started to creep up! Turns out I didn’t grab it fast enough. He turned my calibration ring on my refractometer. It was reading 3.5ish ppt higher than it should. Check my refractometer. 35 ppt it said. Recalibrated it. it was really at 38.5 ppt.

Well well well. $200 well spent. With this story I’ve rescued you from months of frustration.

 

[vetteguy53081]

Not sure if I got the right section but I was hoping to see if I could get help with my apex probe. My probe was working somewhat fine and had consistently 2ish ppt higher than my Hannah salinity checked and tropic Marin hydrometer. I went to do a recalibration two nights ago and the end result is that now my probe is 4 ppt (38) higher than both of my other instruments.

Thinking I messed up, I did another recalibration. I did it the same way but slower. Float the solution near the temp probe for 30 min, Take the salinity prob out, rodi rinse, Pat it dry with a new microfiber cloth, gave it a few shakes to get any air bubbles out.

After the calibration I did notice that the prob was reading 40 ppt in the solution. After about a few hours the salinity settled to 38 ppt again.

Wondering if I these calibrations broke my probe, if I may have calibrated wrong or if I should just shift my alarms to center around the new readings and cross check with my other two tools occasionally

You may have to repeat. probe after calibration come in high and after calibration settles a little . If probe is older, it is susceptible to failure or false readings but also tilt probe in the sump or its location and place at an angle to assure NO bubbles are trapped which will send the reading haywire

 

[bryan3536]

Idk if this works for you but I’m using my hydrometer every few weeks to get a real reading and setting my alarms to be relative. That 38.8 I’m reading is 33.8 on my hydrometer so now I’m just basing that 40 as 35ppt until I decide to recalibrate in a few months

That’s what I’ve been doing, but doing that little calculation bugs me, you know?

 

[Beazy]

That’s what I’ve been doing, but doing that little calculation bugs me, you know?

And that’s why I wanted to fix mine lol. Idk if Neptune support will help, I’m going to enlist them when recalibration time comes around again