Aquarium Marine saltis not justSodium Chloride,it contains very essential minerals that are very important for keeping your marine aquarium. If we speak about the content, there are three things:Magnesium, calcium, Alkalinity. Calcium is very important because the invertebrates and corals have their hard body made of rich calcium content.
Alkalinity is the relative acidity of water or related to the pH of the water. Normal potable water is neither acidic, alkaline, but water with salt is bound to be alkaline. This is essential because bicarbonate is another important component for the good growth of corals.