Water Softeners
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Water softeners remove calcium, magnesium and certain other metal cations in hard water. The resulting soft water is more compatible with soap and extends the lifetime of plumbing.
How Water Softeners Work
The regeneration process explained
Raw or untreated water passes through the mineral/resin tank and the media contained within it. This media is called resin, or zeolite. The calcium and magnesium carbonate in the water (two elements responsible for water hardness) are attracted to the resin media and are removed before exiting the resin tank. When the resin beads are fully coated, they lose their ability to store hardness. It is then that the salt/brine solution is pumped through the resin tank, releasing the hardness stored on the beads. After flushing the residue during the purge cycle, the beads are recharged and ready to store hardness again.
Four Stages of the Regeneration Cycle Explained
Stage 1: Backwash - The initial stage of regeneration. A cross current is produced to rapidly upflow, or "fluff", the packed resin beads so that brine water can be evenly distributed throughout the resin bed.
Stage 2: Brining (Salt rinse) - This is the most important part of the process. A venturi (suction) allows the brine solution to be pumped from the brine tank into the resin tank and is then slowly rinsed through the resin bed, releasing the hardness content.
Stage 3: Purge (Rapid rinse) - A fast rinse, purging residual brine and hardness through the drain. The resin is now ready to store hardness again.
Stage 4: Brine Refill - Water is refilled to the salt storage tank in order to make brine for the next regeneration process.
Guidelines for Setting Water Softener Regeneration Cycles
The four key factors for determining a proper regeneration schedule are:
- The grain capacity contained in the resin tank.
- The amount of water consumed in the home.
- The amount of reserve capacity allowed.
- The amount of hardness present in the water.
Grain Capacity: The amount of resin, generally measured in cubic feet or 1,000 unit increments; 30,000 grains = 1 cubic ft.
Water Consumption: The use of water in the home, calculated in U.S. gallon increments. It is most efficient to determine this figure by obtaining the average water consumption figures on past copies of water department billing statements. If this is not possible, allow for 75 gallons per day average per person, and 75 gallons per day for automatic washer/dishwasher combined.
Reserve Capacity: The amount of grain capacity allowed as a reserve to ensure softened water until the delayed regeneration time occurs.
Water Hardness: The amount of calcium and magnesium carbonate and sulphide, measured in grains per gallon or parts per million.
Water Softener Components
There are three basic components for all water softening systems:
- Contoller (or head)
- Mineral tank (also called the resin tank)
- Brine tank (also called the salt tank)
There are two types of controllers:
- Demand controlled (also called meter controlled), two types:
- Solid state
- Cable and gear driven
- Time controlled (also called day wheel controlled)
There are two types of brine systems:
- Dry brine systems (uses a shelf with water underneath)
- Wet brine systems (no shelf, salt fills the entire tank)
There are three types of power supply:
- 120 volts (standard wall outlet)
- 24 volts (transformer plugs into standard wall outlet)
- Water driven (no electricity used; i.e. Kinetico/Marlo-GLC)
There are two types of regenerant used:
- Sodium chloride (Solar salt, Rock salt, Pellet salt)
- Potassium chloride (K-Life)