# Calcium

Calcium plays a crucial role in a reef tank as it is a vital component of the skeletal structures of many organisms that inhabit the tank, including corals, crustaceans, and mollusks. In fact, calcium is one of the main building blocks of the calcium carbonate skeletons that make up the hard, stony structures of many corals.

In a reef tank, calcium is constantly being utilized by organisms to build and maintain their skeletal structures, and it must be replenished through various means to maintain healthy growth and development. This can be achieved through regular water changes, the addition of calcium supplements, and the maintenance of appropriate pH and alkalinity levels.

Maintaining proper calcium levels is essential for the growth and health of the organisms within the reef tank, as low levels can lead to weakened skeletal structures and poor growth, while excessive levels can result in the formation of harmful deposits and damage to sensitive organisms.