Apex Salinity Probe Issue

[jiminy_crime]

So I recently purchased a brand new Apex and set up all the new probes using proper calibration.

The Apex has now been up and running for about a week now and assume there is a break in period from all that I have read.

The main issue that is coming up is that I have kept my salinity at 1.026 on a refractometer that I doubled checked for accurate calibration and no matter what I do, the salinity probe continues to rise above 36ppt. I have now lowered my salinity on the refractometer from 1.026 to 1.025 over the past few days with the removal of saltwater with fresh RO/DI water.

Any reason the probe would continue to rise despite the reduction SG?

Thanks!

 

[jsker]

Have you hit the apex forum yet? link

 

[Cory]

Any bubbles in the probe will cause it not to work. I had one too and was very dissatisfied.

Id use it only as an alarm (if the ato stays on kill the ato)

 

[hybridazn]

Like stated above make sure there at who air bubbles stuck in or around the probe. The 2 little air purge holes should be submerged. Also temperature plays a part in measuring salinity, a rise and fall in temps could affect salinity readings from the probe. The difference in a reading from 35ppt to 36ppt is very small, something your refractometer most likely can't read. I'm not sure I would fuss too much about this, if the probe ever starts reading off the charts from normal than make sure the probe is clean and recalibrate

 

[Velcro]

Same situation. Red Sea refractometer calibrated with 35 ppt solution but apex reads 36-37.

I ended up using my tank water as the calibration fluid since it matches the calibrated refractometer.

 

[BoomCorals]

To start, you can't compare your refractometer with the apex probe. They measure salinity in two very different ways. The apex probe is more about consistency. It should consistently read around the same reading + or - about 1 ppt.

 

[Randy Holmes-Farley Verified Community Expert]

To start, you can't compare your refractometer with the apex probe. They measure salinity in two very different ways. The apex probe is more about consistency. It should consistently read around the same reading + or - about 1 ppt.

The method doesn't matter. When properly calibrated, they will give the same answer, within the limits of uncertainty of each.

 

[BoomCorals]

The method doesn't matter. When properly calibrated, they will give the same answer, within the limits of uncertainty of each.

Oh interesting, apex said otherwise.

 

[Velcro]

Oh interesting, apex said otherwise.

I would too if I was selling apexes

 

[Randy Holmes-Farley Verified Community Expert]

Oh interesting, apex said otherwise.

I seriously doubt that they dispute what I wrote, but if they did, they are certainly wrong.

 

[BoomCorals]

I seriously doubt that they dispute what I wrote, but if they did, they are certainly wrong.

hah! i love it.

 

[lake985]

Just be happy that it's reading close to your actual levels. Mine has been reading 1.3 (!) since being setup four months ago. I've calibrated it numerous times. I'll contact customer support one day...

 

[JBslick81]

What did apex tell you. I am concerned. I have a APEX in the mail and one large sump containing the heater and protein skimmer. I'm sure to get bubbles I thinking about some sort of shielding to protect the probes. Keep us updated.

 

[BoomCorals]

FWIW mine reads the same as my milwaukee digital refractometer. 35 ppt

 

[Randy Holmes-Farley Verified Community Expert]

What did apex tell you. I am concerned. I have a APEX in the mail and one large sump containing the heater and protein skimmer. I'm sure to get bubbles I thinking about some sort of shielding to protect the probes. Keep us updated.

You can read some comments here:

https://www.reef2reef.com/threads/xplain-ppt-to-srg-no-way-to-convert-apples-to-apples.302825/