How do water softeners work?
Water softeners work by ion exchange, removing calcium and magnesium from the water. When hard water enters the mineral tank, it flows through a layer of resin beads. These resin beads are usually made of polystyrene and carry sodium ions. Resin beads have an anionic or negative charge.
Calcium and magnesium have a positive charge, so only the cations are removed by the water softener. The opposite charges attract each other, so the negative charge of the minerals attracts the positive charge of the resin beads. When hard water flows through the resin, the beads trap the mineral ions and water softener removes them from the water. When the mineral ions from the bead trap are released, the sodium ions are released. As the water flows through the mineral tank, the resin column removes all the hardness and the softened water enters your home.
What are the components of a water softener?
A water softener consists of three parts
- Control valve
- Mineral tank
- Brine tank
The three together remove minerals from hard water, monitor water flow, and clean the system regularly by regeneration.
What does the regeneration process of a water cooler look like?
During the regeneration cycle, the resin coil is filled with a highly concentrated brine solution that cleans the hardness minerals from the system. The coils are then refilled and primed for removal of the hardness minerals. Resin beads are very durable and can effectively soften water for over 20 years. There are two ways of regenerating a water-cooling system: co-regeneration and reverse regeneration (also known as post-salting and pre-salting).
What do water softeners remove?
Water softeners primarily remove calcium and magnesium ions from hard water. Calcium (Ca2+) and magnesium (Mg2+) are the minerals that make water hard. The ion exchange process attracts and removes all positively charged ions (also known as cations). These ions can include other minerals such as iron and manganese.
Is soft water suitable for drinking?
Soft water is suitable for drinking. The ion exchange process releases sodium into the water as the resin beads trap the harder minerals. However, the sodium content of soft water is harmless because it is much lower than we often think: for moderately hard water, for example, 5 grains per gallon (about 86 ppm), you only need to add 37 mg of sodium per gallon. This is less than 2% of the recommended daily intake of sodium. A slice of white pasta contains about 170 mg of sodium and a slice of pizza contains about 640 mg of sodium. Therefore, the sodium content of water coolers is relatively low.
The amount of sodium added to a water softener is linearly related to the reduction in mineral hardness. For every milligram reduction in water hardness, the water softener releases two milligrams of sodium. This is only a problem if you live in an area where the water is very hard. If the water hardness in your home exceeds 400 ppm, you will need to install a reverse osmosis system to purify the water you use for drinking and cooking.
A reverse osmosis system passes water through a semi-permeable membrane and removes almost all solids and dissolved salts from the water. If you have blood pressure or kidney problems and your doctor has told you to reduce your sodium intake, we recommend that you install a reverse osmosis system after your water softener. Also make sure that the cost of a reverse osmosis system in Pakistan is affordable for your household.
