I've been doing some reading on supplementing calc/alk/mag. Up until now I didn't have a need. I was looking into making my own supplements and keep seeing people using mag flake for the recipes. I can't find any locally but did see it available online. I have a few bags of Combotherm made by Dow that contains calcium chloride, potassium chloride, and Sodium chloride. http://www.ice-melt-products.com/f/Combotherm.pdf the problem is that about half of the flakes contain a green dye. The dye disappears after use ( it also states this on the bag). Is this safe to use for calc/alk/mag recipes?