I ordered magnesium sulfate and didn't order the mag. chloride and was wondering if dosing Magnesium sulfate alone would be OK. Im no chemist, but there must be some reason to mix both together.
By using Epsom salt (magnesium sulfate) only, your sulfate concentration will rise. You can reduce the rise by doing water changes. I'll let Dr. Randy Holmes Farley explain HERE....all the way at the bottom of the article, just before "Summary".