Hay guys, seem to have a situation, have a in balance in my testers all have been calibrated with calibration fluid. Hanna is 33ppm,refractor is 35ppm, apex after cal in saltwater 34.8ppm,should I trust the refractor since there is no electrical interference or the Hanna calibrated with the 35ppm fluid it comes with. it seems the Hanna is way off thanks guys…
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