Apex salinity issue

[Frederick Edwards]

My hydrometer reads 34, but my apex says it is at 36.7. Any ideas?

 

[jaws789832]

How often do you calibrate the apex. They are pretty finicky. Also make sure your calibration fluid is not expired. I had some packets that were expired about a month and I figured it would be ok. how off could it be. It threw my probe way off and once I got some fresh packets everything went back to normal. I would recommend getting a refractometer though. Hydrometers are not that accurate and hard to read.

 

[AcanthurusRex]

Air bubbles. You must put the probe in a place that has no bubbles to collects inside. I found I must invert the probe underwater to completely get the air out of the probe.

 

[pickupman66]

When was last time you calibrated your probe? Also hydrometer are known to be the lease accurate device to measure salinity.

 

[Frederick Edwards]

How often do you calibrate the apex. They are pretty finicky. Also make sure your calibration fluid is not expired.

Everything is brand new.

 

[Frederick Edwards]

Calibrated 2 hours ago.

 

[jaws789832]

Did you calibrate it? even brand new you must calibrate it for accuracy.

 

[Frederick Edwards]

Air bubbles. You must put the probe in a place that has no bubbles to collects inside. I found I must invert the probe underwater to completely get the air out of the probe.

I will try this.

 

[SashimiTurtle]

Chunk the hydrometer and get a refractometer.
I use this one,
https://www.amazon.com/gp/aw/d/B01A...ff77-58dd-939c-15e25c67585c&pf_rd_i=393272011

and this is the calibration fluid,
https://www.amazon.com/gp/aw/d/B005...Mwebp_QL65&dpPl=1&dpID=41r3m4A9nuL&ref=plSrch

 

[trido]

Brand new doesnt mean anything if you did not calibrate it. If you did calibrate it, I would trust its reading long before a swing arm hydrometer.

 

[pickupman66]

Btw, I have an Archon and not an apex and the probes on both can be finicky. They are bubble magnets and they register off. I made this out of a 1/2" shark bite t and 1/2" of tubing. It is the feed to a reactor and run by an mj600. No trapped bubbles here. No leaks either! It has been Rock steady ever since.

And I would believe new calibration fluid over a hydrometer every day.

 

[Frederick Edwards]

Brand new doesnt mean anything if you did not calibrate it. If you did calibrate it, I would trust its reading long before a swing arm hydrometer.

Calibrated 2 hours ago

 

[dmax525]

Give it a few days to settle in also. I just installed my apex late last week and it took a few days for the salinity probe to settle down. Also I wouldn't rely on it to give you your exact salinity reading just watch to see how stable it is over time. Keeping it in the water for water changes and etc help and keeping it out of any sump compartment with air bubbles is a must I wouldn't run it in the skimmer chamber for example.

 

[Frederick Edwards]

So, I am gonna get a refractometer tomorrow. I will get my salinity where I want it to be with refractometer. Once that is established, can I then calibrate the probe with the water in my sump?

 

[Frederick Edwards]

Give it a few days to settle in also. I just installed my apex late last week and it took a few days for the salinity probe to settle down. Also I wouldn't rely on it to give you your exact salinity reading just watch to see how stable it is over time. Keeping it in the water for water changes and etc help and keeping it out of any sump compartment with air bubbles is a must I wouldn't run it in the skimmer chamber for example.

If I keep it in the refugium, will the heat from my light hurt the probes?

 

[Robink]

Mine was off too. Even after calibration. It took about a week or two for it to become accurate. I double check with a refractometer weekly. Just in case.

 

[Cperkins]

Milwaukee digital hydrometers are the way to go

 

[Frederick Edwards]

I purchased a refractometer and took a reading and my apex probe is matching up. I'm good to go. Thanks for the help everyone.

 

[SethOF]

I purchased a refractometer and took a reading and my apex probe is matching up. I'm good to go. Thanks for the help everyone.

Remember that the Apex conductivity probe, the hydrometer and the refractometer are measuring different things.

 

[B-ridge]

I'm having similar issues but my salinity probe changes depending on tank temperature which I'm told it shouldn't do
Before I had issues with my refractometer my salinity probe and refractometer were spot on