Magnesium is necessary for calcium building marine and reef animals, but is naturally depleted in your aquarium. Keep your aquarium's magnesium levels at a healthy level with Brightwell Hydrat-MG Hydrated Magnesium supplement. Magnesium is also known to help control bryopsis algae.
Maintains an elevated magnesium concentration, in excess of 1500 ppm, relative to the average natural seawater concentration, for a prolonged period of time to benefit your reef aquarium. This solution is for experienced aquarists only.