Why test? Invertebrates (stony corals and soft corals, sponges, sea urchins, crustaceans, mussels, snails etc.) and the popular red coralline algae found in marine water require sufficient levels of calcium for healthy growth. The natural calcium level of the sea is 390–440 mg/l. In order for the organism to make the best use of the calcium, the correct ratio of hydrogen carbonate must also be present in the water. For this reason adding calcium compounds without hydrogen carbonate (such as calcium chloride), is pointless. A calcium level of 400–480 mg/l has proved to be ideal for marine aquariums. In addition to calcium, magnesium in sufficient quantities and in the right proportion to calcium is required for the optimal skeletal and shell structure of these organisms. The natural magnesium content in the sea is approx. 1300 mg/l. In the marine aquarium a magnesium content of 1200 to 1400 mg/l has proven to be ideal.

JBL ProAqua Test MgCa Magnesium/Calcium
+ one drop of Mg reagent 2 = 100 mg/l magnesium
+ one drop of Ca reagent 3 = 20 mg/l calcium
+ includes syringe to measure amount of water