The Kalkwasser Stirrer 1000 stirs the kalkwasser so that the calcium carbonate sediment settles at the bottom of the Stirrer while the clear solution of calcium hydroxide is at the outlet where it can be transferred to the tank using the Niveaumat SP3000 (Automatic Top Off Unit with peristaltic pump and float switch).Unit comes with 1 lb of Aqua Medic Kalkwasser Powder. For replacement Kalkwasser we suggest using the Inland Seas Kalkwasser Mix Calcium Supplement.