There are three generally used methods to deliver useable calcium to your reef aquarium. These include the use of a calcium reactor, kalkwasser reactor, or dosing additives. A fourth, less commonly used method, at least here in the states, is through the dosing of balling liquids. The balling method is quite popular in Europe, as it provides a steady stream of calcium, carbonate, trace elements, and magnesium to the reef aquarium. These liquids are usually delivered via automated pumps, which deliver precise amounts of each additive to the tank at predetermined times of the day. The attractive part of this method of calcium delivery is the fact that it bypasses the time and labor involved in manually dosing two-part additives, and it doesn’t impact pH like a calcium reactor or kalkwasser stirrer. It’s sort of the best of both worlds…automated simplicity. For a long time though, the dosing pumps were very expensive, making the method almost untouched in the US. Fortunately, dosing pump prices have come down significantly and other less expensive brands have arrived on the scene.