4. Different ways to soften water
There are many options that you can choose from when finding ways to soften your water. Each approach has benefits that might fit your special needs.
Resin-based water softeners. There are two major types of customary water softening units: Time clock and DIR. The distinction between them has to do with the unit’s approach to the regeneration cycle.
One conventional water softener with increasingly limited use in recent times is the “time clock” softener. It operates with a timer that triggers regeneration when the resin is estimated to be saturated with hardness based on water hardness levels and water usage calculations. The timer settings can be determined through simple calculations, but changes in water quality, as well as water usage levels, can lead to problems including overuse of salt and water.
The most common type of water softener now on the market and now in use is called a “demand-initiated regeneration” (DIR) unit. These units keep track of the water usage and then trigger regeneration based on various factors, including amount of water used, electrical conductivity of the resin, or by monitoring the hardness of the effluent. Once one of these parameters reaches a set level, the regeneration process is initiated. These DIR water softeners are very reliable in sensing the need for regeneration and reduce the occurrence of problems associated with time clock units described earlier. These DIR systems can be very efficient in both the amount of salt or water used compared to the amount of hardness removed.
Taken from the CASS study, the following is one example that demonstrates the difference between the two:
With an average daily soft water use per home of 300 gallons, assuming 2.7 people are in the home, each person would use 111 gallons per day.
- With a time clock unit, 15,000 gallons of water per year would be needed to regenerate and 1,217 pounds of salt.
- A DIR unit would use approximately 4,258 gallons of water and 973 pounds of salt per year.
- This represents a 60 percent savings in water and 20 percent savings in salt with the DIR unit compared to a time clock unit.
Distillation. This water softening process uses heat to vaporize water and remove impurities. Simply put, pure water molecules are taken away from contaminants that have a higher boiling point than water. There are many systems on the market to accomplish this goal, but they all follow the same basic principles. First, water is first heated until it reaches the boiling point. It then it starts to evaporate. The temperature must be kept at a constant temperature during this process.
Any evaporated water is “captured” and taken through a system of tubes to another container. In this way, the steam condenses back into its original liquid form. Contaminants having a higher boiling point than water remain in the original container. The process removes many minerals, bacteria and viruses, and any chemicals that have a higher boiling point than water from drinking water. Included in this list: Salt. During a distillation process, hardness ions (Ca2+ and Mg2+) are left behind, along with other contaminants.
Distillation is in many respects an ancient, simple and reliable way to treat water. In many circumstances, however, it is relatively expensive. What is more, distillation may not treat every one of the issues a particular customer is concerned about.
Reverse osmosis (RO) is one of the most common water treatment systems on the market. It uses hydrostatic pressure gradients across a special membrane. Water molecules can pass through the membrane, but hardness ions such as Ca2+ and Mg2+ remain behind and are flushed away by excess water into a drain. The resulting water supply is free of hardness ions without any other ions being added. But it should be noted that membranes have a limited capacity, requiring regular replacement.
Portable Exchange (PE) uses resin-based softening technology but ensures that the resulting salinity does not enter the water sources. With PE, water softening tanks provide soft water to homes and businesses by exchanging exhausted resin with newly regenerated resin on a regular, as needed, basis. The spent resin is regenerated at a centralized treatment facility under a controlled environment with brine reclaim and reuse which greatly reduces salt discharge. PE is not available in every community, however, and there are likely to be cost considerations.
“Alternative” salt-free softening devices. For many years, numerous firms have promoted what they call “salt free” softening systems. These claims can potentially cause confusion. It is important for customers to understand that water softening is the removal of calcium and a few other minerals that can cause water to damage pipes, appliances and clothing.
Some alternatives that do not remove the hardness minerals sometimes claim to be scale control devices. However, no national third party testing and certification system has been created by the manufacturers of these products, so it is difficult to verify and compare claims.
Remember too that only softeners are demonstrated to extend the life of water-using appliances and plumbing and even your clothes. You also do not need to use as much soap when doing dishes or laundry.