I used the "ultra-pure" water that came with the refractometer to calibrate it.
I just tested the 53 mS fluid on the refractometer and it tested 38 pts!
Oh man... I had a marine tank for a year in the past and always went by the refractometer thinking it was absolute. Having it off by 3 pts is a big deal. It troubles me that these companies and fish stores don't tell you this.
|