Like calcium and strontium, magnesium is used in the calcification of skeletons of reef organisms. In many cases, magnesium is used in place of calcium for calcification. In addition to its role in calcification, magnesium is used by organisms ranging from bacteria, to coralline algae to fish.
How can you be sure if magnesium levels are deficient? There are a couple of indications; severely depleted levels of magnesium (below 800 mg/L) can cause depressed pH levels and an inability to maintain proper calcium levels (more on ionic imbalance).The best way to tell if you need a magnesium supplement, though, is to test for it using a magnesium test kit such as Seachem's Reef Status™: Magensium & Carbonate and Borate Alkalinity.
If you've determined your magnesium levels are low, supplementation with ions™ is necessary. ions™ restores magnesium by employing the most concentrated (90,000 mg/L), fully dissolved magnesium and does so without adding any ammonia. Other liquid magnesium supplements inherently contain ammonia because the magnesium chloride used in their production contains ammonia. This is a result of the mechanisms for deriving and/or producing magnesium chloride. aquavitro has gone to considerable lengths to remove this contaminant and a proprietary process makes ions™ the first and only liquid magnesium supplement that does not contain ammonia.
Using a fully dissolved magnesium is critical. Some magnesium supplements use a magnesium source that is simply not soluble, that is, unavailable. This means it can never be utilized by reef organisms, and is, consequently, of no value. If the product itself is milky white or the instructions direct the user to shake well, more than likely, a substantial amount of magnesium is not being utilized (the same is true of calcium products). ions™ also includes strontium and boron in the NSW ratio of 1.7:1 to avoid ionic imbalance with long term use.