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Mineral Chemistry

Calcium (Reef)

Dissolved calcium ions in reef systems - the primary building material corals use to build their skeletons.

Unit: ppm Code: CALCIUM

📊 Ideal Ranges

Reef
400-450 ppm

📖 Overview

Stony corals extract calcium from seawater to build calcium carbonate skeletons. Natural seawater is 420 ppm; reef tanks target 400-450 ppm. Growing SPS-heavy tanks consume calcium rapidly and require daily replenishment via two-part additives, calcium reactors, or kalkwasser dosing.

📈 How to Raise

Two-part calcium supplements (Balling method). Calcium reactor. Kalkwasser (limewater) dosing. Manual calcium chloride additions.