What Type Of Refractometers Are Best

[kandymann]

I use Marine Depot Pro Refractometer and it is designed specifically for NSW. Easy to calibrate and consistent. I love it.

 

[Randy Holmes-Farley Verified Community Expert]

One thing to is the calibration solution needs to be new. I got some old stuff once and it read much higher. I also have some older bottles I kept in the basement that read higher than newer bottles?
Randy what would cause this? Does water evaporate in plastic bottles over time or do the bottles degrade?

Evaporation is the only thing I can think of that would increase salinity in a standard.

 

[GreatWhiteTang]

Any that is kept calibrated, within reason if it's descent and kept calibrated this will not make or break a system imo.. Used glass hydrometer and needle type for many years before getting a refract and now that I have one I have no difference in the quality or accuracy of my salinity in display water.