General Hardness is probably the most important, unchecked water parameter. General Hardness (GH) refers to the amount of Calcium and Magnesium salts (mineral salts - Sulphates, Carbonates, and Bicarbonates) present in the water. General Hardness has a considerable effect on pH and the ability of pH buffers that keep the pH stable as these mineral salts have a carbonate or bicarbonate component, they may also affect the Carbonate Hardness (KH) or Alkalinity. While KH can be tested, it only provides a measure of the buffering capacity of water, it does not measure all mineral salts present. When monitoring your hardness, GH is the preferred parameter to check as it is more complete than KH.
Replenish™ is a proprietary blend of salts designed to replenish physiologically relevant minerals that are removed by reverse osmosis or deionizing filtration. Replenish™ restores General Hardness (GH) using a balanced blend of both "soft" (sodium, potassium) and "hard" (calcium, magnesium) salts. Restoration of mineral content is essential since a complete lack of minerals will result in osmotic stress in those species whose osmoregulation systems are adapted to a mineralized environment. Severe osmotic stress can result in osmotic shock which will lead to rapid death.
Dose: 5mL to 40L to raise GH by 1meq/L(2.8dGH).
Check out the General Hardness care cheet by copy and pasting this link into your web browser - www.tropicalmarinecentre.com.au/downloads