Where would one find magneisum chloride hexahydrate?
That's much harder. From the article:
Magnesium chloride hexahydrate made by the Dead Sea Works is sold at many home stores, including Home Depot. It is often labeled MAG Flake. It may be repackaged as meltsnow:
http://www.meltsnow.com/msds-mag-flakes.htm
It may also be available from these stores:
http://www.harveysalt.com/prod01.htm
http://www.meltsnow.com/products-dry-magnesium-chloride.htm
and
Substitutes for Dead Sea Works Magnesium Chloride Hexahydrate
The Dead Sea Works is a business unit of ICL Fertilizers. They sell magnesium chloride hexahydrate in the US as a deicer and also apparently to artificial seawater (salt) manufacturers. In the past, potential impurities (such as ammonia) have left many aquarists and even some companies wary of using deicing or any other grades of magnesium chloride hexahydrate. However, The Dead Sea Works company recently supplied a detailed impurity profile for its product listing most impurities (29 of them in all). None were high enough to be a concern to reef aquarists. Included was an indication that it had adequately low ammonia. Subsequent analysis by Greg Hiller of some of the supplied material confirmed that the ammonia is low enough to use.
The recipe above is based on the bulk density of the MAG Flake as supplied by the manufacturer. They also sell a pellet product. It may be OK to use, but probably has a slightly different bulk density (they do not provide it that I can find). Exact values for the magnesium part are less important than the other parts, and when using pellets Iââ"šÂ¬Ã¢"žÂ¢d just follow the directions as stated here for flake unless better information is supplied in the future.
At this time, magnesium chloride hexahydrate from the Dead Sea Works is the only such product that I recommend, but there may be others that are acceptable. Choosing other unknown brands may be fine, or not. Iââ"šÂ¬Ã¢"žÂ¢ve not tested them for purity.
