PART 3 – Magnesium
Other than the two reactors described above, the only thing I dose is Randy Holmes Farley’s recipe for magnesium as needed to maintain the tank magnesium demand. The recipe below comes straight from Randy Holmes Farley and is specifically for use with a calcium reactor.
*** Note this recipe is different from that given in Randy’s two-part recipe. In that recipe more magnesium sulfate is necessary to offset the rise in chloride that is provided by both the calcium chloride and the magnesium chloride.
Using both Epsom salts and MAG flake, dissolve 7¼ cups MAG flake and ¾ cup Epsom salts in one gallon of water, and use the mixture to supplement magnesium in amounts determined using the magnesium section of the online calculator (http://reef.diesyst.com/chemcalc/chemcalc.html), using the drop down entry "Randy's Recipes 1 and 2 Versions A and B.
Note that combining the two materials in solution can result in some precipitation of calcium sulfate (calcium and sulfate are impurities in the MAG flake and the Epsom salts, respectively. To assure yourself that the two materials have fully dissolved, dissolve each separately in some freshwater before
combining them. Some calcium sulfate precipitation is acceptable, and it is okay to let the solids get into the aquarium, assuming you can dose in a way that prevents them from landing on delicate organisms.
All of Randy Holmes Farley’s reef aquarium related articles can be found at the link below. I have found this series of articles to be priceless and owe the success of my tank to his work. http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605