Food grade Magnesium Chloride (Magnesium chloride-6hydrate, MgCl2-6H2O) for maintaining and raising magnesium level in reef aquariums by Balling method. Magnesium supplement is important in reef aquariums with shell forming life forms like stony corals and invertebrates.

Magnesium chloride and Magnesium chloride-6-hydrate have the same effect in reef aquariums, the difference is that magnesium hydrate contains water molecules. The higher is the hydrate value, the higher is the number of water molecules; 6-hydrate contains six water molecules.

NOTE! Magnesium can be added to a reef aquarium as magnesium chloride or as magnesium sulfate, both of which can be consumed by shell forming aquarium inhabitants. The difference is that magnesium chloride also increases chloride level while magnesium sulfate increases sulfate level in aquarium water. Both chloride and sulfate are components of sea water, but as either of them is consumed by aquarium life, their concentration in aquarium water will slowly increase and eventually become problematic. It is important to maintain both CHLORIDE and SULFATE levels as optimal as possible, due to which it is recommendable to supplement magnesium as both magnesium chloride and magnesium sulfate.

In practice:

If CALCIUM is supplemented as Calcium CHLORIDE, magnesium is supplemented by dosing 5 parts of Magnesium CHLORIDE and 3 parts Magnesium SULFATE (8 parts total). This way the total CHLORIDE level increase is comparable to the SULFATE level increase.

If CALCIUM is supplemented as KALKWASSER / LIMEWATER (which does not contain either chloride or sulfate), magnesium is supplemented by dosing 10 parts of Magnesium CHLORIDE and 1 parts Magnesium SULFATE (11 parts total).

NOTE! Magnesium is consumed by aquarium life, while the chloride part is not. This will eventually increase the chloride concentration in the aquarium water, which can be avoided by using sodium chloride free aquarium salt mixture in water changes once in a while OR by doing a major water change once a year. A large annual water change will both restore the levels of all important sea water components and remove hazardous element concentrations.

Sold in a 20kg sack.