Magnesium is essential for the growth of healthy, attractive corals. The optimal magnesium concentration in a marine aquarium is 1,250 – 1,400 mg per litre (ppm). Easy-Life Magnesium is a concentrated product which is ideal to use to compensate for a deficiency. Use weekly or after measurement 10 ml per 30 litres (1 fl oz per 24 US gallons) raises the Mg-concentration with 10 ppm.