Will this work for refractometer calibration

[mark freshwater]

Hi i found this , everyone seems out of stock or its hard to find in australia its for pools

 

[reefwiser]

we keep the saltwater in our aquariums at 35,000 ppm. This is only at 6440 ppm
Look at this thread on making your own calibration solution
https://www.reef2reef.com/threads/diy-salinity-calibration-solutions.220052/