Neptune Conductivity Probe
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thabizness
New member
Following. I have a appointment with Neptune Monday because of bad calibration of pH and salt probes on the new Apex
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BaltimoreFish
New member
I used the BRS (Bulk Reef Supply) video as my guide. I followed it exactly and it worked perfectly. This was a year ago-not sure if Apex made changes since to hardware/software.
With that said, it did take my conductivity probe a few months to "settle down" and provide accurate values.
With that said, it did take my conductivity probe a few months to "settle down" and provide accurate values.
I don't think they've changed anything. I recall when I first got the PM2 + probe it was a pain on the a$$ to get it calibrated. Three years on, new probe, still required 5 calibration attempts to get it close (I rely on my refractometer for accurate readings). Just seems like there must be a better way!!!
f3honda4me
New member
I have a call with apex Tuesday for a PH probe that won't read above 7.6 on my Neptune.
Neptune Conductivity Probe
I've had reasonable luck getting the pm2 probes calibrated, but what I've found is that you should leave it in the tank for a good 1-2 weeks before calibration, then don't clean it when you calibrate it. I believe that it develops a thin film of bacteria or algae or something that affects the reading. If you calibrate before that film forms or clean the film off when you calibrate then it will slowly drift out of calibration over the next week or two as the film reforms. Cleaning the probe is ok to do occasionally if you want, but just don't recalibrate it until it's been back in the tank for at least a week or two after the cleaning.
You don't need to worry about getting it super dry for the calibration either. Usually what I do is swish it around in the tank water a bit to shake off any loose stuff on it, then just shake it out and blow into the end of the probe or use some compressed air to get out 99% of the water.
The thing that frustrated me the most, though, was that I discovered that no two calibration solutions are the same. I tried the neptune solution, two different brands from amazon, and Randy's homemade solution and they were different by at least 1ppt and as much as 3ppt. Since I run my tank at 35ppt according to my refractometer, what I finally wound up doing was just calibrating the salinity probe using tank water.
I've had reasonable luck getting the pm2 probes calibrated, but what I've found is that you should leave it in the tank for a good 1-2 weeks before calibration, then don't clean it when you calibrate it. I believe that it develops a thin film of bacteria or algae or something that affects the reading. If you calibrate before that film forms or clean the film off when you calibrate then it will slowly drift out of calibration over the next week or two as the film reforms. Cleaning the probe is ok to do occasionally if you want, but just don't recalibrate it until it's been back in the tank for at least a week or two after the cleaning.
You don't need to worry about getting it super dry for the calibration either. Usually what I do is swish it around in the tank water a bit to shake off any loose stuff on it, then just shake it out and blow into the end of the probe or use some compressed air to get out 99% of the water.
The thing that frustrated me the most, though, was that I discovered that no two calibration solutions are the same. I tried the neptune solution, two different brands from amazon, and Randy's homemade solution and they were different by at least 1ppt and as much as 3ppt. Since I run my tank at 35ppt according to my refractometer, what I finally wound up doing was just calibrating the salinity probe using tank water.
Ive given up the using calibration solutions for the probes.
As with Brett, calibration fluids are so different its frustrating.
I now just go through the calibration and dry out probe for half an hour. then start the calibration using the keypad, when it says to calibrate to 53000, I just put it back in the tank water which I know is set at the correct salinity.
the only other issue I have had in the past is they do not like air stuck up under near the probe bulb. make sure to give it a little shake in the water to disperse any air which is stuck, if its close to a baffle, air can be drawn in when it overflows and then get stuck under the probe causing it to go out of calibration.
As with Brett, calibration fluids are so different its frustrating.
I now just go through the calibration and dry out probe for half an hour. then start the calibration using the keypad, when it says to calibrate to 53000, I just put it back in the tank water which I know is set at the correct salinity.
the only other issue I have had in the past is they do not like air stuck up under near the probe bulb. make sure to give it a little shake in the water to disperse any air which is stuck, if its close to a baffle, air can be drawn in when it overflows and then get stuck under the probe causing it to go out of calibration.
You have to get the bubbles out of it, that's the key. Make sure during calibration that you hold it on a slight angle with the venting port up. Give it some good taps.
But the issue isn't really calibration, it's air bubbles from placing it in the tank. I found that the best way is to insert it into the sump/tank upside down to guarantee no bubbles then put it in the probe under water. It's been rock solid since then. If you can't do that, you'll have to angle it and shake/tap vigorously ... You'll see the air bubbles fly out.
It's air bubbles, I'm positive. The design of the probe does not handle them well.
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But the issue isn't really calibration, it's air bubbles from placing it in the tank. I found that the best way is to insert it into the sump/tank upside down to guarantee no bubbles then put it in the probe under water. It's been rock solid since then. If you can't do that, you'll have to angle it and shake/tap vigorously ... You'll see the air bubbles fly out.
It's air bubbles, I'm positive. The design of the probe does not handle them well.
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I don't doubt that; however, if the probe is THAT sensitive to bubbles, surely a line or two in the instructions would be warranted. Plus, finding a bubble free spot in the sump isn't easy, so if a bubble can throw off the reading so easily, the thing isn't worth much for control is it. Lastly, as noted above, my various calibrations solutions (all tagged as 53) are not consistent.
f3honda4me
New member
After my call with apex, it sounds like my PH probe is bad. They are sending a replacement. I know yours was salinity probe, but I wanted to mention since PH was mentioned by others.
I'd like to get the salinity probe as I didn't get it with this used 2016 apex, but if it's that sensitive to bubbles I might just pass.
I'd like to get the salinity probe as I didn't get it with this used 2016 apex, but if it's that sensitive to bubbles I might just pass.
I have been able to resolve my issues by using tank water to calibrate and by making sure to swish it around. It's now reading 35.5 which is where my refractometer is. Now need to calibrate a new pH probe - old one was reading 0.3 high. Now I've got a low pH problem :lol:
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