Water hardness refers to the amount of calcium and magnesium ions dissolved in water. These ions enter the plumbing with the water; during heating, pressure changes or evaporation they lose their solubility and build up on surfaces as calcium carbonate, in other words limescale. Most mains water in Turkey falls within the moderate to high hardness range; that is why limescale is not a regional exception but an operating problem encountered in almost every facility.
Hardness is measured in French degrees (°fH) or German degrees (°dH). Roughly, 0-7 °fH is considered soft, 7-15 °fH moderately hard, 15-30 °fH hard and above 30 °fH very hard. The measurement can be made on site with a simple test kit; however, it is always better to have a full water analysis done before selecting a system. This is because, in addition to hardness, the iron, manganese, chloride and conductivity values also directly affect the choice of equipment.
The cost of limescale is often invisible. Even a thin layer of scale on a heating surface noticeably reduces heat transfer and means more energy is needed to reach the same temperature. In steam boilers, heat exchangers, cooling towers and hot water lines, the build-up creates the risk of sudden breakdowns, pressure drops and unplanned shutdowns as well as efficiency losses. On the domestic side, it shortens the life of taps, shower heads, washing machines and dishwashers and increases detergent consumption.
The solution is to remove the hardness at the source. Water softening systems based on ion exchange swap the calcium and magnesium ions in the water passing through the resin bed for sodium ions; when the resin is exhausted, it is regenerated with brine and reused. Depending on the flow rate and operating regime, single-tank, volumetric or, in facilities that need uninterrupted water, duplex (tandem) configurations are preferred. A correctly sized system eliminates both scale-related breakdowns and energy losses.
