I ordered this refractometer from Amazon based on the raving reviews on this forum. Lots of people mentioned how easy and accurate it was. Plus you only calibrate it with RODI/distilled water. Provides a digital readout.
I’ve had it since October, 21st, 2021, and I have used it religiously…until I got my first Apex with the salinity probe.
I made @Randy Holmes-Farley Conductivity calibration solution and calibrated the Apex perfectly. It didn’t make sense how my Apex read 34ppt , but the refractometer would say 35ppt.
Plus, the Milwaukee would say 35ppt but when I switched the the s/g mode with the same sample of water, it would show 1.027 which makes no sense.
Tonight I made Randy’s calibration solution for my refractometer (refractometers and conductivity testers use different calibration solutions). I had a refractometer which I used before October 2021 which I calibrated with Randy’s solution at the time, but I made a new batch of calibration using my accurate scale and the refractometer showed 35ppt on the dot.
The same calibration solution (for refractometers) was placed in the Milwaukee unit and it read 37ppt.
In addition, Milwaukee states an accuracy of +/- 2 PSU/PPT. So that reading was “acceptable”.
Finally, I placed my tank’s water in my calibrated manual refractometer and it showed 34ppt, which exactly matched the conductivity apex probe, while the Milwaukee stated my tank was 35-36ppt.
I do not recommend the Milwaukee salinity tester for people who wish to maintain tanks with sensitive corals. Maybe this unit would be best suited for those who maintain FO (Fish Only) tanks, or maybe even soft coral tanks.
Randy’s article for the DIY salinity calibration recipes for any tool used to measure salinity in reef aquariums: http://reefkeeping.com/issues/2004-06/rhf/index.php
Happy Reefing.
I’ve had it since October, 21st, 2021, and I have used it religiously…until I got my first Apex with the salinity probe.
I made @Randy Holmes-Farley Conductivity calibration solution and calibrated the Apex perfectly. It didn’t make sense how my Apex read 34ppt , but the refractometer would say 35ppt.
Plus, the Milwaukee would say 35ppt but when I switched the the s/g mode with the same sample of water, it would show 1.027 which makes no sense.
Tonight I made Randy’s calibration solution for my refractometer (refractometers and conductivity testers use different calibration solutions). I had a refractometer which I used before October 2021 which I calibrated with Randy’s solution at the time, but I made a new batch of calibration using my accurate scale and the refractometer showed 35ppt on the dot.
The same calibration solution (for refractometers) was placed in the Milwaukee unit and it read 37ppt.
In addition, Milwaukee states an accuracy of +/- 2 PSU/PPT. So that reading was “acceptable”.
Finally, I placed my tank’s water in my calibrated manual refractometer and it showed 34ppt, which exactly matched the conductivity apex probe, while the Milwaukee stated my tank was 35-36ppt.
I do not recommend the Milwaukee salinity tester for people who wish to maintain tanks with sensitive corals. Maybe this unit would be best suited for those who maintain FO (Fish Only) tanks, or maybe even soft coral tanks.
Randy’s article for the DIY salinity calibration recipes for any tool used to measure salinity in reef aquariums: http://reefkeeping.com/issues/2004-06/rhf/index.php
Happy Reefing.
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