Salinity Testing Issues

[VinTheFin]

Recently I had my Hanna tester go bad, it wouldn’t hold calibration and was reading my tank as 1.024 and LFS tested it at 1.030. That’s how I found out cause I suspected something was wrong because I would add salt but kept reading 1.024. (It’s a nano tank before people say I’m stupid for continually adding salt, doesn’t take much in a 5 gallon) Hanna sent me a new one. I also ordered the Milwaukee MA887 brand new cause I didn’t want to use Hanna anymore and out of the box it read its own calibration fluid of 1.025 as 1.028. I tried like 10-15 times recalibrating and testing my water, using their samples, my own RODI water and DT water, even tried to test the Hanna calibration fluid that is supposed to be 1.026 and it read it as 1.018? I then ordered the Veegee STX-3 and it just got here and if I calibrate it to 1.000 using my RODI water it reads my tanks at 1.028. My replacement Hanna is here too and it reads my tank at 1.025. Someone please tell me what to do lol, I have all these testers and none of them even slightly resemble the other. Is there a place I can pay to ship my water to be tested to know 100% where it’s at? Then calibrate the Veegee to match?

 

[chipmunkofdoom2]

Calibrating with fresh water only works if your device is perfect and has no inaccuracy over its range of measurement. You'll get much more consistent results if you measure with a calibration fluid. You can buy them at Bulk Reef supply, or make your own.

 

[VinTheFin]

Calibrating with fresh water only works if your device is perfect and has no inaccuracy over its range of measurement. You'll get much more consistent results if you measure with a calibration fluid. You can buy them at Bulk Reef supply, or make your own.

I used the calibration fluid for both Milwaukee and Hanna, the ones they come with. Refractometers are calibrated with RODI from what I’ve read or no?

 

[JZ199]

calibration fluid is the way to go, I think most tests/calibration fluids are a few ppm apart. I've heard nothing but great things about the Milwaukee testers. I forget what the other test is called but I know a lot of people send in for an ICP analysis test and that will tell you absolutely everything you can imagine about your water.

 

[VinTheFin]

calibration fluid is the way to go, I think most tests/calibration fluids are a few ppm apart. I've heard nothing but great things about the Milwaukee testers. I forget what the other test is called but I know a lot of people send in for an ICP analysis test and that will tell you absolutely everything you can imagine about your water.

I will look into that, my idea is to get a for sure 100% reading on my water and then since the VeeGee is known for keeping calibration for years I can set it and then send in my water every year or so.

 

[KStatefan]

I used the calibration fluid for both Milwaukee and Hanna, the ones they come with. Refractometers are calibrated with RODI from what I’ve read or no?

Good article on refractometers by Randy Holmes Farley

https://reefkeeping.com/issues/2006-12/rhf/index.php

 

[homer1475]

Easiest thing to do is to make your own calibration fluid.

https://reefkeeping.com/issues/2004-06/rhf/index.php

Very simple to do. You also cannot use the hanna calibration packets on the milwaukee or the refractometer. Your trying to use a conductive calibration fluid on an optical device.

 

[TangerineSpeedo]

A conductive tester (Hanna) and a Refractometer are most likely not going to read the same. Hanna measures the conductivity of NaCl, where a refractometer measures the how light refracts through NaCl and all of the other elements in your water (trace, etc.) it is not a significant difference, but it is a difference. I have the luxury of using NSW as a reference, so when I calibrate my Hanna with their fluid at 35ppm my local NSW reads 32.5-33 ppm. You can buy a NSW reference that has trace elements in it and use that to see where you lie after calibration of the Hanna. Also the difference with your Milwaukee is within there margins I believe.

 

[VinTheFin]

Easiest thing to do is to make your own calibration fluid.

https://reefkeeping.com/issues/2004-06/rhf/index.php

Very simple to do. You also cannot use the hanna calibration packets on the milwaukee or the refractometer. Your trying to use a conductive calibration fluid on an optical device.

Okay that makes sense for the crazy difference then!

 

[VinTheFin]

I just made the calibration for Hanna, conductivity part. It came out to 1.026 so I’ll use that for now and do the other two I have tomorrow. Thank you everyone for the insight it was all very helpful!