refractometer gives different results

[Smells Fishy]

So I recalibrated it and double checked it and got different salinity levels. Did this numerous times and not being right on to where it should be. After each time I ran it under hot water and dried with paper towel. I also get varies result when testing the reef tank as well....Help, thanks.

 

[redfishbluefish]

Do not clean your refractometer by running it under hot water. I can't even begin to guess what this does to the ATC (automatic temperature compensation). Simply squirt saltwater or RO/DI water over the platlet and lightly wipe with a lint free cloth.

 

[Smells Fishy]

Hell i been doing that a long time...... I best replace it!

 

[Rob.D]

Hell i been doing that a long time...... I best replace it!

If you are going to replace it, consider the Red Sea refractometer...I've owned a half dozen from different manufacturers and the Red Sea brand has been the most reliable tool.

 

[JimWelsh]

The Vee Gee STX-3 model refractometer is designed for use with seawater, and not NaCl brine. It has Boomer's blessing, which says a lot! Item # 43036, VEE GEE STX-3 Handheld Refractometer On VEE GEE Scientific, Inc.

 

[Downbeach]

Did you calibrate it/them with a 35ppt calibration solutionhttp://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18718? If not, you might want to get some, calibrate them, and then do your test.

 

[Smells Fishy]

I did calibrate with the 35ptt. I rinsed with r/o only this time and dried with cotton cloth and results came out much more on point over n over. Live n learn, thanks for the suggestions everyone.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, this has more on refractometers and how to use them:

Refractometers and Salinity Measurement by Randy Holmes-Farley - Reefkeeping.com