Basic: Dissolve 2 grams (~½ teaspoon) of product per 20 US-gallons of aquarium water in 8-fl. oz. of fresh water; stir immediately prior to use and add every other day to provide important elements to reef-building organisms. May also be added directly to an area of high water flow. When used in this fashion, 400 g treats up to 4,000 US-gallons (15,141.6 L). May temporarily cloud aquarium water after addition, therefore it is recommended that the product be dosed at night.
Advanced: Create a stock solution by dissolving 20 grams (~5 teaspoons) of Elemental in 8-fl. oz. of fresh water (preferably purified); each ml of stock sol’n will increase the calcium concentration (”[Ca2+]”) in 1 US-gallon (3.785 L) of water by 5.1 ppm, alkalinity by 0.213 dKH, strontium by 0.100 ppm, magnesium by 0.015 ppm, and potassium by 0.003 ppm. Stir stock sol’n vigorously immediately prior to addition. If initial [Ca2+] in aquarium is below 412 ppm, add stock sol’n at maximum rate of 10 ml per 20 US-gallons daily until desired [Ca2+] is attained, then dose daily or weekly as needed (see below). Maintain [Ca2+] within a range of +/-10 ppm. Once desired [Ca2+] has been acquired, measure aquarium's [Ca2+] at the same time each day over a one- to two-week period to determine the daily rate of calcium uptake (i.e. the decrease in calcium). To determine daily dosing rate (preferable to weekly dosing): estimate volume of water in entire aquarium system (US-gal.); divide the daily decrease in [Ca2+] by 5.1; multiply this number by volume of water in system to obtain daily ml of stock sol’n required to maintain stable [Ca2+].