Help with Salinity and Calibrating my Refractometer

[jstlsn]

I have an ATC Refractometer that I purchased on ebay about 6 years ago. Every once in awhile I use the PINPOINT Salinity Calibration Fluid to calibrate the refractometer. I recently calibrated my refractometer and it was way off. So I corrected the calibration and then measured my tank water and it was at 1.031. Obviously way to high. However, I am not seeing any problems in my tank. Fish are happy, eating and swimming around. Corals look happy with polyps out. RBTA looks happy.

Now I started to think something was off with my Calibration Fluid. So, I ordered some new PINPOINT Salinity Calibration Fluid and a new Sybon HD Refractometer from Premium Aquatics. They arrived yesterday. I read the instructions for the new Sybon HD Refractometer and it states that it is professionally calibrated at the factory and does not need immediate calibration. I tested the calibration with the ultrapure water that was included and it was 1.000. I then tested the calibration with the NEW bottle of Calibration fluid and it was 1.028. Now I am getting frustrated. So, I tested the calibration with the OLD bottle of Calibration fluid and it was 1.026.

Now I have two bottles of PINPOINT Salinity Calibration Fluid that give different readings and two different refractometer that may or may not be calibrated correctly. Any advice on how to figure out what is actually correct? I don't trust anything at this point.

Thanks
Brad

 

[jstlsn]

Bump

 

[snorvich]

That is a problem. Pinpoint calibration fluid is supposed to be 1.0264. I guess I would calibrate to the new bottle assuming there was some contamination in the old bottle. I think you cannot calibrate using pure water but I don't recall the reason; it was in one of Randy's articles.

 

[MeuserReef]

I always just use RO water to calibrate my Refractometer. I didnt even know that there was a profesionally sold calibration product!