How Does a Water Softener Work
Water hardness occurs do to the presence of calcium, magnesium, and manganese ions in the water. These chemical ions are collected by the water as it travels along it’s normal course through the ground. The level of hardness that is characteristic of any given water source is heavily dependent on the presence of ions in the soil, streams, and rivers within the region. In the US, the highest concentration of ions is found in the Midwest with decreasing levels found toward the Coastal states.
How Does a Water Softener Work?
There are many different types of water softeners available on the market that can be used to reduce the affect that ions have on the hardness of the water supply in a home. There are positives and negatives associated with each type of water softener and it is important for individuals to determine for themselves which qualities are most important to them. For example, it is often the case that the most effective water softeners contribute to high levels of salt in the environment while less effective products do not produce as much of a salt concentration in the water that is being passed into the waste water system. You will be in a better position to make a satisfying purchase decision once you have answered the question how does a water softener work.
Salt Based Softening Systems
The traditional approach to softening water involves a system that uses sodium chloride or potassium chloride to carry out a chemical cation exchange that replaces calcium and magnesium ions with sodium or potassium ions. In general, this type of system consists of a tank that houses the exchange resin and a tank that contains the salt that is used for the regeneration process. As water passes through the resin tank, calcium and magnesium are removed. Most resin beds have a capacity limit when it comes to removing ions and they must be washed with salt once the limit has been reached. The limit for any given system is dependent on the size of the bed. As the system nears its softening limit, the bed is washed with a salt solution and the ion exchange process occurs. The calcium and magnesium are then directed into a drain and the salt is washed from the resin bed so that the system can soften additional water.
There are many different types of salt based systems available including metered based, microprocessor meter, electro mechanical meter, time clock based, and twin tank. To understand how does a water softener work, it is important to have a basic understanding of each of these options.
1) Metered based water softener – has a single resin tank and a separate salt tank that have a fixed capacity to remove ions from the water. These types of softening systems go through a regeneration process each time the resin limit is reached. They are called a metered softener because they keep track of the level of water used and initiate regeneration only when it is needed. Over time, these systems cost less than a timed system because they work to conserve salt and water.
- Microprocessor meter – a turbine spins as water is consumed and an electronic sensor communicates the rate of spinning to the computer control system. This information allows the computer to decide when the regeneration process should be initiated based on the water hardness level set by the user.
- Electro-mechanical meter – uses a similar turbine to that of the microprocessor meter, but is connected to a meter by a cable. Once the capacity has been reached, an electrical motor initiates regeneration.
2) Time clock based water softener – has a single resin tank and separate salt tank, but does not monitor the water consumption and regenerates at a preset time. The exact day that regeneration occurs is dependent on the type of schedule that has been set by the user. These systems will generally cost more over time because they do not work to conserve salt and water.
3) Twin tank water softener – has two resin tanks and a separate salt tank. In general, twin tank systems are metered using either a microprocessor or electro-mechanical meter. The benefit of having two tanks is the fact that one tank is always available for softening while the other is being regenerated. Although these systems do cost more, they offer the ability to provide uninterrupted supplies of softened water.
Salt-free Softening Systems
A thorough answer to the question how does a water softener work requires that we consider both salt-based and salt-free systems. Although salt-based softening systems are generally considered to be more effective, they do drain off high concentrations of salt into the environment that can contribute to negative environmental outcomes. Individuals who are concerned about this affect should consider using one of the many salt-free alternatives that are currently on the market. The technology used by these systems depends on the product under consideration and may include things like nucleation assisted crystallization (NAC), chelation, magnetohydrodynamics, and electromagnetic waves.
1) Nucleation assisted crystallization (NAC) – changes the structure of calcium and magnesium ions so that they form a crystal structure that does not deposit as scale. This process does not remove ions from the water and does not add any salt to the municipal water system.
2) Chelation – describes the way in which ions bind to metal. Systems that use this process make the ions soluble so that they wash away with the water rather than deposit in pipes, on pots, and around bathroom fixtures. Softeners that use chelation work similar to detergents that are sold for individual use.
3) Magnetohydrodynamics – it modifies the polarization of mineral salts. These typically consist of a magnet that is placed on a pipe leading to the home’s main plumbing system.
4) Electromagnetic waves – alters the form of calcium and magnesium ions so that they do not adhere to a metallic surface. Systems that use this process usually consist of wires that are wrapped around a water pipe that leads to the primary plumbing system in the home.
Purchasing a Water Softener
As you can see, there is no one answer to the question how does a water softener work. There are many different types of systems available that use a variety of different techniques to remove or alter calcium and magnesium in the water. The appropriate system for your home depends on which aspects of each system you value most. If you are looking for a softener that is highly effective and you are not concerned about the salt that it adds to the environment then a salt-based softener may be right for you. However; if you are looking for a system that is moderately effective and that adds no salt to the municipal water supply then your best option is to select one of the salt-free alternatives.