Correct, bag out of water, temp probe in bag. If the bag was really cold or hot for some reason I’d bring it up to room temperature first so it wasn’t changing during the calibration process.
(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor
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Correct, bag out of water, temp probe in bag. If the bag was really cold or hot for some reason I’d bring it up to room temperature first so it wasn’t changing during the calibration process.
Thought you all might be entertained by my recent experience. My salinity probe was flaky and so I had given up on calibrating with the pouch of standard. I tried Randy's recipe, but still struggled to get it working right. I decided I'd just get my tank to 35 ppt (using refractometer and Randy's refractive index standard) and calibrate in-tank. But it bugged me that I couldn't figure it out. So one more go. Calibrate in the pouch and let the probe sit in the pouch. ~35 ppt. Calibrate with Randy's conductivity recipe and let it sit in the recipe. ~35 ppt. Move the probe to the tank ~50 ppt. And BTW, the probe wire is routed away from all others, I'm floating the standard in the sump to equalize temperature, I'm shaking to get rid of the air, temp compensation is on, tank at ~77.
So then I exchange a couple of emails with Neptune and we do a share-your-screen call. First thing is it probably needed to be reset, which he did. One thing he mentioned was to make sure you restart the Apex quickly after the fake calibration. Next thing we did was run through some calibrations with the Neptune pouch and Randy's recipe. Probe always read correctly when left in the standard, but move it to the tank and it reads high. Did this multiple times. Did the same with tank water in a tupperware, just like we did with Randy's recipe. Support's conclusion was that there was stray voltage/current somewhere, so he suggested turning off each piece of equipment one at a time. I'm impatient so I turned everything off all at once and still it reads high. I'm starting to suspect there's a galvanic couple somewhere so I start pulling equipment out of the sump. Still reads high.
Somehow it occurred to me to put the probe in the tank (reads high) then, without taking the probe out of the water, put the tupperware underwater, then up and around the probe, then lift the two together out of the tank keeping the probe underwater. Still reads high! Eureka!
So here's the deal, I was shaking the probe more vigorously in the tank and sump than I was in the pouch or tupperware. What is really surprising to me is how consistent I was at getting two different calibrations. @SuncrestReef is spot on: you need to calibrate with the probe upside down. The vent holes in the probe are not adequate to allow the air to escape.
You can test this yourself. First, do a manual calibration using tank water in a small baggie or tupperware where you can't shake it vigorously. Note the reading as it settles out. My reading in this situation was remarkably consistent at 550-600. Next calibrate in tank by shaking the probe with it upside down. In this case my reading was ~800.
Sorry so long-winded. Hope it was helpful.
So then I exchange a couple of emails with Neptune and we do a share-your-screen call. First thing is it probably needed to be reset, which he did. One thing he mentioned was to make sure you restart the Apex quickly after the fake calibration. Next thing we did was run through some calibrations with the Neptune pouch and Randy's recipe. Probe always read correctly when left in the standard, but move it to the tank and it reads high. Did this multiple times. Did the same with tank water in a tupperware, just like we did with Randy's recipe. Support's conclusion was that there was stray voltage/current somewhere, so he suggested turning off each piece of equipment one at a time. I'm impatient so I turned everything off all at once and still it reads high. I'm starting to suspect there's a galvanic couple somewhere so I start pulling equipment out of the sump. Still reads high.
Somehow it occurred to me to put the probe in the tank (reads high) then, without taking the probe out of the water, put the tupperware underwater, then up and around the probe, then lift the two together out of the tank keeping the probe underwater. Still reads high! Eureka!
So here's the deal, I was shaking the probe more vigorously in the tank and sump than I was in the pouch or tupperware. What is really surprising to me is how consistent I was at getting two different calibrations. @SuncrestReef is spot on: you need to calibrate with the probe upside down. The vent holes in the probe are not adequate to allow the air to escape.
You can test this yourself. First, do a manual calibration using tank water in a small baggie or tupperware where you can't shake it vigorously. Note the reading as it settles out. My reading in this situation was remarkably consistent at 550-600. Next calibrate in tank by shaking the probe with it upside down. In this case my reading was ~800.
Sorry so long-winded. Hope it was helpful.
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I was about to give up on the salinity probe all together, and then I came across some info about using a probe storage bottle filled with calibration solution. Insert the probe, turn the bottle upside down and gently shake and tap it. You’ll be amazed how many air bubbles leave the probe.
When all the bubbles stop, calibrate the probe. Worked perfectly.
I haven’t touched the probe since other than to use a soft tooth brush to clean it off from time to time.
@DWill, Exactly! I thought, "surely I'm shaking it hard enough!" while right-side up. Wrong.
I used a plastic baggie. I'll get the storage caps (https://www.bulkreefsupply.com/brs-ph-orp-probe-tip-soaker-bottle.html) as soon as I accumulate enough things to get free shipping.
I used a plastic baggie. I'll get the storage caps (https://www.bulkreefsupply.com/brs-ph-orp-probe-tip-soaker-bottle.html) as soon as I accumulate enough things to get free shipping.
Flameback Pair
started reefing 1999
What does this mean and what is a fake calibration?
I left the calibration solution in the sump overnight. My conductivity probe had been in the sump for about a week. Temp probe reading 77.3 and I verified salinity right on 35.0 with refractometer.
I did the manual calibration. I set TC at 2.2.
I took the probe and dipped into RO water a few times. Wiped off outside and then used cotton cloth to wick all of the water from water from the tip. I started manual calibration and it stabilized at 67. Opened the solution bag, placed the temp and salinity probe into bag. I used my fingers to seal around the probe the best I could and gently turned upside down. I lost a slight amount of solution. Immediately placed bag back into sump and let stabilize. Reading was 492. I checked the salinity reading on the Apex, and it was at 40!
I did this twice with same results. I went ahead and placed the probe into the sump and inverted it a couple of times to get the bubbles out. After 10 minutes, my salinity reading was 35.1 !! It's been between 34.9 and 35.3 for 5 days.
Not sure why it was reading 40 in the bag. Hope this helps.
I did the manual calibration. I set TC at 2.2.
I took the probe and dipped into RO water a few times. Wiped off outside and then used cotton cloth to wick all of the water from water from the tip. I started manual calibration and it stabilized at 67. Opened the solution bag, placed the temp and salinity probe into bag. I used my fingers to seal around the probe the best I could and gently turned upside down. I lost a slight amount of solution. Immediately placed bag back into sump and let stabilize. Reading was 492. I checked the salinity reading on the Apex, and it was at 40!
I did this twice with same results. I went ahead and placed the probe into the sump and inverted it a couple of times to get the bubbles out. After 10 minutes, my salinity reading was 35.1 !! It's been between 34.9 and 35.3 for 5 days.
Not sure why it was reading 40 in the bag. Hope this helps.
Flameback Pair
started reefing 1999
@eag when do you restart the Apex and what is the fake calibration.
Sorry so late to reply. Check out this link: https://www.reef2reef.com/threads/apex-salinity-probe-calibration.377968/page-2#post-4619407
From the post: "disconnect the probe from the jack on the Apex controller. Now do a manual calibration. Obviously this is a sham (i.e. fake) calibration since no probe is attached, so just go through the steps quickly and finish it. Then reboot your Apex."
I can't recall, but maybe you need, or easier, to do the fake calibration manually, that way you don't have to worry about settling time and being in range.
The Neptune support guy said to me to do the reboot, "quickly". Don't know why.
From the post: "disconnect the probe from the jack on the Apex controller. Now do a manual calibration. Obviously this is a sham (i.e. fake) calibration since no probe is attached, so just go through the steps quickly and finish it. Then reboot your Apex."
I can't recall, but maybe you need, or easier, to do the fake calibration manually, that way you don't have to worry about settling time and being in range.
The Neptune support guy said to me to do the reboot, "quickly". Don't know why.
The reason my reading was high in the solution after calibration is that I'm on a 10 minute data cycle. I didn't wait long enough. Duh
I just went through another calibration, the same way, and reading is spot on.
I just followed the instructions carefully to calibrate the probe. The good news is that I get very stable consistent readings, the bad news is they are consistently wrong. It reads 29 PPT both in the Apex calibration fluid and in the tank. Using 2.2 TC with tank at 77.5.
Any thoughts?
Any thoughts?
I think this probe is a waste of money and space. I know some people are able to get it to work right with hacks and techniques but when you pay that much for a salinity probe it should work without having to shake it or do this or do that. I love the apex system and use a lot of neptune products and love their support bu honestly they need to improve this probe asap. My 2 cents. I just use the hanna refractometer, the one that looks like the Milwaukee and its awesome
@raylinwhen which instructions did you use: Neptune's or this thread's? When you say it is reading 29 ppt in the cal fluid, is this immediately after calibration before removing the probe from the cal fluid? Did you calibrate it upside down? Did you install it in your tank or sump upside down?
Thanks for the response. I calibrated multiple times, including the instructions from this thread. I inverted during calibration, but did not mount it upside down in my sump. It would be difficult to do so and if it didn't help in the calibration, I'm not sure it would help in the tank.
The reality is that it seems to be functioning properly- it is very stable and reacts the way one would expect during ATO and water changes. I may try to contact Neptune tech support, but it is still helpful if I just use 29 PPT as my tank's baseline.
Neptune support was very friendly and helpful to me, but didn't quite understand the significance of the problem of air bubbles and the need to invert the probe and vigorously shake it.
I ask about the calibration because, by definition, you are telling the probe what reading to associate to 35 ppt. So if immediately after cal, and still in the fluid, it says 29 ppt, then something is amiss. My 1st suspicion is it needs to be reset/restarted. https://www.reef2reef.com/threads/apex-salinity-probe-calibration.377968/page-2#post-4619407
If that doesn't do it, definitely call Neptune.
I ask about the calibration because, by definition, you are telling the probe what reading to associate to 35 ppt. So if immediately after cal, and still in the fluid, it says 29 ppt, then something is amiss. My 1st suspicion is it needs to be reset/restarted. https://www.reef2reef.com/threads/apex-salinity-probe-calibration.377968/page-2#post-4619407
If that doesn't do it, definitely call Neptune.
Ya I’ve also tried this and even bought the probe containers to hold the probe and be able to invert it but I still get a very low reading. I haven’t used my tank water as the calibration for 35 becuase I don’t care about the number the apex reads anymore, I just use it to track swings. It reads low but seems to be consistent so it’s at least useful for seeing any changes.
If you calibrate in sump, and it reads 35, then something is definitely wrong with your cal procedure with the standard solution. If in-sump cal also reads 29, then it could be your procedure, but it might also be needing reset/restart or it may be a faulty probe.
Oh, one problem with mounting rightside up in sump/tank is microbubbles may collect inside and gradually throw the reading off. I'm using a suction cup from an old heater and orienting it so the probe is 45 degrees off vertical but upside down. The torque on the probe from it's weight and the cord keeps it lodged in the suction cup's ring. Not the best, but working so far. Long term I don't know. I've heard long-term submersion of the cap and cord can degrade them. We'll see. One option would be to wrap some permeable membrane (wife's stocking?) around the end of the probe to keep bubbles out. Then it might work rightside up with some delay due to lower flow into the sensor. (Any other viewers with any other ideas?)
Oh, one problem with mounting rightside up in sump/tank is microbubbles may collect inside and gradually throw the reading off. I'm using a suction cup from an old heater and orienting it so the probe is 45 degrees off vertical but upside down. The torque on the probe from it's weight and the cord keeps it lodged in the suction cup's ring. Not the best, but working so far. Long term I don't know. I've heard long-term submersion of the cap and cord can degrade them. We'll see. One option would be to wrap some permeable membrane (wife's stocking?) around the end of the probe to keep bubbles out. Then it might work rightside up with some delay due to lower flow into the sensor. (Any other viewers with any other ideas?)
I did the in-sump cal, and that worked.
One way to test your salinity probe's ability to track changes is to stop topping off. The salinity should slowly rise. You can calculate the expected amount based on fresh water evaporated and confirm your probe is giving something reasonable.
One way to test your salinity probe's ability to track changes is to stop topping off. The salinity should slowly rise. You can calculate the expected amount based on fresh water evaporated and confirm your probe is giving something reasonable.
Be aware of Data log time. Mine is set at 10 minutes, so once I do the calibration I put it in the sump, clear bubbles, and wait for 10 minutes.
Sorry for the repeat.
Also, don't be afraid to adjust TC to get matching readings.
Sorry for the repeat.
Also, don't be afraid to adjust TC to get matching readings.
Flameback Pair
started reefing 1999
@keithIHS , @SuncrestReef and others: what have you done for mounting the salinity probe besides cordside down on a 45* angle for dealing with bubbles? Does anyone know what long term effects this would cause to the blue endcap? Does anyone have any ideas how to protect the endcap?
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