Physical Water Conditioning
Electronic and Magnetic Water Softeners
This covers a range of products that include:
They are all intended to reduce the scale build up.
These devices are usually relatively small in size and installed close to the point where the water enters the premises in order to treat the whole of the water supply. They are either plumbed into the pipework so that the water flows through them or they are wrapped around the pipework. They are generally simple to install but some require electricity.
The basic principle is that they encourage the formation of crystals as the water flows through them. When the water is then heated, the scale tends to form around the crystals rather than on the internal surfaces of the boiler or pipework.
The advantage of physical conditioners is that they have typically a low purchase price, low installation cost and are low maintenance. However, their performance is often unpredictable. They will, at best, only reduce the rate at which scale deposits build up. They do not reduce the hardness level of the water and so will not provide benefits in terms of soap and detergent reduction and removal of scum around kitchen and bathroom sanitary ware. Also they don’t change the quality with respect to its suitability for drinking.
Sometimes it can be necessary to install more than one device, particularly in larger homes and, if there is a storage tank, additional devices are often needed on the tank outlets because the effects wear off while the water is sitting in the tank.
Chemical treatment involves the addition of chemicals to the water. There are chemical dosing products for treating the whole house supply. These generally use a polyphosphate-based chemical and they are intended to reduce scale and corrosion. The dosing devices come in cartridge form and they are plumbed into the water supply. As the water passes through the cartridge a small amount of chemical is dissolved into the water.
In the main, however, chemical treatment is used on the primary circuit in central heating systems to prevent the boiler, pipework, valves and radiators from scaling and corroding. This will not affect the scale deposits, scum formations or the hot water system.
The central heating system only needs to be dosed once - not continuously, but it may need topping up every few years or after the system has been drained down for maintenance. The chemical is usually added directly into the header tank.
Chemical treatment works by coating the inside of the pipe and plumbing equipment with a very small layer of polyphosphate which protects the surface from corrosion and scale build up. Any crystals of scale which form in the bulk of the water are similarly coated and they stay in suspension rather than stick to the surfaces of the system.
They are effective in reducing scale and corrosion. In fact, the water supply companies dose the water with polyphosphate to reduce dissolution of lead pipework and help to achieve the lead level required by the Drinking Water Regulators. However, for domestic dosing products, the cartridges need to be changed annually, and some people do not like the concept of adding chemicals to the water in their home.