Refractometer/Hydrometer/GHL

[airdrie5]

Originally Posted by sphelps

All the calibration fluids including the fresh water should the same temp as the tank. The profilux has a density offset that also needs to be set after calibration. If it's a good quality refractometer and calibrated properly I would use that as the guideline and set the profilux offset to match. You can try RO or distilled water with the refractometer but it shouldn't make a difference.

Thanks for the info. The refractometer is a Sybon salinity and I assume its not a bad quality one. I will use the refractometer as a guideline to set my GHL but it still puzzles me that the hydrometer and the Pinpoint are not within the same parameters.

GHL: 1.0213
Pinpoint: 53.0 (1.026)
Instant Ocean Hydrometer: 1.025
In-sump bobbing Hydrometer/Temp: 1.022