De-Ionised Water prevents furring and scale formulation in batteries and steam irons. 5 litre bottle of de-ionised water ideal for 12V battery refills. De-ionised Water - Ideal for water cooling. Use in conjunction with UV Fluids / Additives for the perfect mix that you require. Ideal for hard water areas. Specification: Calcium Carbonate alkalinity less than 15 parts per million. Insoluble impurities, less than 10 p.p.m.