Apex users...Question

[SweetReefOH]

I have calibrated this salinity probe 3 times. It seems like it just wants to continue raising the salinity. Its either faulty, or I'm not taking something into consideration. Any ideas?

Temp=78.5
Calibrated refractometer test=1.026
ATO in place and working properly

The only thing I can correlate is the pH dropping at night. Would that increase salinity??

[CoralBeauties]

wall_tank would be the one to answer that question.  I was thinking of adding a pm2 with the salinity probe but seems to be alot of posts on the apex forum with problems with getting them calibrated and working right.
Jeff

[SweetReefOH]

Ya I seen that too. I ended recalibrating it again and so far, it's reading steady. I posted on the Apex forum and the moderator said you have to soak the probe for a week before it will read accurately. Really? Why don't the instructions say that? Oh well, I'm just glad it seems to be working.

[CoralBeauties]

I have an orp probe on my system and they also say it needs to run for a good week before it is reading very accurately.  Did you find a cheaper outlet for the pm2 and probe?  The probes are crazy expensive, main reason mr cheapo here hasnt added one to my apex.
jeff

[SweetReefOH]

I got the new wi-fi Apex. It came with all the probes

[Nbehnken]

I have had continued problems with my salinity probe. I believe it has to do with electrical interference from nearby equipment. If I pull it out of the sump and drop it in a calibrated solution then it reads fine. As soon as I put it back in my sump it's low by 5ppm. I did put a ground probe into my sump just encase there was any stray voltage but it didn't help. I pretty much just monitor it for any major changes swings.

[ricksastro]

I finally got mine to be steady by getting my tank to be exactly 35 ppm based on a refractometer calibrated with 35 ppm fluid and then calibrated the probe with the tank water.   Since I did that, it's been spot on and steady.

[Crimsonvice]

I literally just asked this question to the Neptune support team, because I purchased a 2016 Apex and just set it up. I asked why they don't say in the instructions to let the probes sit in your water for a week before calibrating, or to let the calibration fluid float before calibrating. They said it is not necessary in every instance. Yet it seems that everyone has the same problem, so why not just modify the instructions to reflect that. Lol. He said it can take up to 4 weeks for the probe to read steady.


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[SweetReefOH]

I finally got mine to be steady by getting my tank to be exactly 35 ppm based on a refractometer calibrated with 35 ppm fluid and then calibrated the probe with the tank water.   Since I did that, it's been spot on and steady.

That's a good  work around. I think I will do that. I haven't calibrated mine since that first week a couple of months ago and it has gone from 35.4 to 38.6! Slowly increasing for no reason what so ever. Needless to say, my salinity has not changed in 2 months w/ my calibrated refractometer.

[CoralBeauties]

opening this old thread up.  I calibrate my probe and it reads 35 in the calibration fluid but when I place it in my tank I get a pretty steady 31.5  I would like it to match my refractometer, can I adjust the temp setting to change the apex reading to closely match my refractometer?  From reading seems as if this is a common issue.
thanks
Jeff

[Wall_Tank]

Yes it is difficult to match.  Temp compensation is very sensitive.  There are a few threads on the neptune forum explaining how to do it properly......but it still probably wont match your refractometer.

[Wall_Tank]

Jeff,

This is the thread I was referring too.  https://forum.neptunesystems.com/showthread.php?19352-Best-practice-in-calibrating-the-2016-salinity-probe