The Aqua Medic reefdoser EVO 4 is a 4-channel dosing unit with external controller and optinal expansions module. The Aqua Medic reefdoser EVO 4 can independently control the four dosing pumps included in the package. The dispensing of the food or additive can be achieved either manually or automatically. All pumps can be calibrated individually. The interval control allows for adjustment of the duration of the on/off cycle for each pump over a broad time span - from seconds to days. The external controller can be placed in a position away from the pumps to make it easy to use and allow for very simple programming. The Aqua Medic reefdoser EVO 4 is expandable to eight dosing pumps with reefdoser add 4Aqua Medic reefdoser EVO 4 can automate many tasks in an aquarium:+ regular dispensing of trace elements and fertilizers in salt- and fresh water aquarium+ controlled addition of calcium and bicarbonate into coral reef aquaria+ accurate dosing of Kalkwasser+ automatic feeding with live zoo