Calcion by Brightwell Aquatics is a calcium supplement designed to maintain optimal levels of this essential element in reef aquariums. Calcium is crucial for the growth and health of corals, clams, tube worms, and other calcifying organisms that build aragonite skeletons. By maintaining calcium within the range of 412 - 450 ppm, Calcion ensures these marine creatures can thrive when provided with appropriate lighting and water conditions. It works seamlessly alongside Alkalin8.3 to balance pH and alkalinity levels, creating an ideal environment for coral growth.