Tommy
1. Measure ? cup of Morton's Iodized Salt (about 73.1 g).
2. Add one teaspoon of salt (making about 79.3 g total salt).
3. Measure the full volume of a plastic 2 L Coke or Diet Coke bottle filled with purified freshwater (about 2104.4 g).
4. Dissolve the total salt (79.3 g) in the total water volume (2104 g) to make an approximately 3.65 weight percent solution of NaCl. The volume of this solution will be slightly larger than the Coke bottle, so dissolve it in another container.
1. Get some Morton table salt
2. Scoop up 1 level teaspoon.
3. Measure out 2114 ml = 2.114 liters of water and put in a container.
4. Add teaspoon of salt to water
5. Stir well till dissolved
6. Fill coke bottle, that is that is your cal solution storage container.
6. Put drop on refract cal to read 35 ppt or 1.0264
7. Refract now good for seawater narrow range. 30 - 40 ppt.