Biologically ideal form of calcium for reef aquariums. Adds all 70 trace elements including strontium, molybdenum and iodine. Only natural substances are formed when dissolved. Add directly to your tank, no need to premix or drip. Supplies calcium for corals and co2 for the zooxanthellae. Will not influence ph of aquarium if used as directed. Measured amount of calcium in a truly ionically balanced formula.