Which salinity to believe?

[Chipp]

my apex which i just calibrated the probe says salinity is 32.2 or 1.0243 (using hamzasreef.com salinity claculator) my refratcometer says 1.025 and the icecap tester says 1.022.

 

[PDR]

Have you calibrated your refractometer recently?

 

[Old Fritz]

Did you calibrate the refractometer? If not Id do that. ive never used the snowcap so i can't speak for its accuracy. However two tests are near each other so id trust the refractometer and the Apex.

 

[Chipp]

Have you calibrated your refractometer recently?

I have not and after i tested with it i broke it. The plastic piece was stuck and I forced it, but i just ordered another one with calibration fluid. I assume it was okay tough because it was close to the salinity of the apex, but the icecap tester isn’t close at all to the other two. The icecap tester supposedly doesn’t need calibration.

 

[Chipp]

Evidently you can reinitialize the icecap, so i did. Now i get a reading of 1.023. I wish it had another decimal point because if it was 1.0238. That would be alot closer to to the apex probe.

 

[Chipp]

Got another refractometer and calibrated it as per the instructions and it matches the apex at 1.024-1.025. I retested with the icecap and it was 1.023. So i think i am going to stop using the icecap tester.

 

[Chipp]

Okay so I just did the ATI icp analysis and my salinity came in at 30.82 which would be 1.0232. So now that is the same as the icecap tester. I got calibration fluid and calibrated both the apex salinity probe and my refractometer again and they are both the same at 32.2.

 

[Pntbll687]

Are you having issues with the tank? Corals receded or no polyp extension?

I'm just not really following why you're worried about a .01 difference in salinity

 

[Old Fritz]

If you have two products that both say the same salinity i would trust those over only one product giving you a different reading

 

[Chipp]

Are you having issues with the tank? Corals receded or no polyp extension?

I'm just not really following why you're worried about a .01 difference in salinity

I guess i am just being cautious. This is my second attempt at coarals (i just started adding a few frags) and the first attempt was a disaster. The tank has been going great and when things go great i just expect problems.

In fact last week i posted a message about my chalice frag having two white spots and it turned out to be two small pieces of gravel. I felt like an idiot. I guess i am just gun shy about failing.

 

[User1]

Apex - calibration.
Refractor - plastic or digital - calibration.
Highly recommend test fluid to double check.

I use the Apex just for a guidline and not accuracy even after it is calibrated. I have calibration fluid that after I calibrate my meter I'll double check. I also have an emergency older plastic one that is also marked and used as a reference. So as long as the apex is reading like it normally does I am good. When it is off I know the other devices will report more accurately how far if this makes sense.

 

[Cory]

You should make a diy calibration fluid. Randy holmes farley has an article.

 

[afuel]

With calibration fluid coming and a new refractometer you can be confident in the salinity and be able to sleep at night so just take a deep breath

 

[JumboShrimp]

I love my Icecap because I love my Icecap. Not very scientific of me— sorry! Lol

 

[jsker]

I lost confidence in the Apex after messing with calibration several times, and both a digital refractometer. I would say the ice cap would be your best bet.

The best way to find out is check the ice cap with a calibration fluid

 

[JumboShrimp]

In addition to the main convenience factor, my gut tells me (from using it) that the Icecap is at the very least “consistent”— can’t prove “accurate.”

Consistent = all 3 of my darts are grouped close together.

Inaccurate = the group of 3 darts are in the WALL!

 

[RichReef]

I just went through all this.

A correctly calibrated, well maintained refractometer can't be beat.

Sorry everyone else. Truth is truth.

 

[HOOPDEEZ]

Yeah my apex is consistent but not accurate. I trust my refractometer because it is checked and calibrated often with calibration fluid, I trust my apex to alert me if anything changes, even though the reading isn’t correct. Public service announcement: DON’T use RODI to calibrate your refractometer!