Sea Salt

Sea salt is used in two ways: for the first fill of the aquarium and at every water change. Fresh salt water restores the elements that corals and other animals have used up, so the salt's composition affects water stability over the long term.

Salts differ mainly in their calcium, magnesium and carbonate content. In a tank with fast-growing stony corals a richer salt helps, while a fish and soft coral tank does well with a standard one. If you already dose Balling solutions, remember that a richer salt raises the same values.

Mix the solution in a separate container from reverse osmosis water, let it circulate and warm up for a few hours and check salinity with a refractometer before it goes in. Reef tanks are usually kept at about 35 ppt. Never add salt straight into the aquarium, as undissolved grains can harm the animals.