Fill a 1-gallon container 1/2 full of RO/DI or distilled water and then add 5 1/4 cups of BRS Magnesium Chloride and 2 cups of BRS Magnesium Sulfate into the container. Secure the cap on the container and shake it for about 10 seconds to help start the dissolving process. Remove the cap and fill the container the rest of the way with RO/DI or distilled water. Give the container a few more shakes and then let it sit until all the salts have fully dissolved before use.