Calcium chloride

[Jimmy Nix]

We have neither of the Calcium products in Costa Rica since it never snows here, hence I found a Calcium cloride for use in our houses and closets to assorb humedity. Talked to the company cemist and he told me it if 77% pure. The problem is he does not know what the other 23% is, but I know they use in the brewing of beer so this is my question, How do I know if it will be safe to use in my reef tank or how can I find out. Need help-very imporant.
Thanks Jimmy

[mixed_reefer]

Im not familiar with brewing but if they are putting it in a "food" type of product i would think it might be OK for your reef.

[Randy Holmes-Farley]

77% pure calcium chloride is always calcium chloride dihydrate, with the material other than the 77% being mostly water. Same is true for Dowflake. That said, it is impurities at the sub 1% level that are still a concern.

Unfortunately, even being food grade does not ensure that it won't have as much bromide as the new Dowflake (which may be too much), but it likely does eliminate most other impurity concerns (assuming it truly is a recognized food grade).