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Where softeners are installed in rural areas, dry wells frequently can provide excellent drainage for the unit. In effect, such installations use the earth as a filter. Naturally such installations should follow local codes closely. Once proper drainage is provided, the unit is usually ready for operation.

The installer should load the softener or filter, backwash, disinfect and place the unit in operation and check the results. In general, it is not necessary to regenerate a new softener. Especially important at this point in the installation of a softener is the matter of disinfecting it. Essentially this process calls for the addition of chlorine to the unit. Why is this essential?

Industry Standard S-100, Appendix ii, "Methods for the Disinfection of Water Softeners," states the following:

"The materials of construction of the modern water softener will not support bacterial growth, nor will these materials contaminate a water supply. However, the normal conditions existing during shipping, storage, and installation indicate the advisability of disinfecting a softener after installation, before the softener is used to treat potable water. In addition, during normal use, a softener may become fouled with organic matter, or in some cases, with bacteria from the water supply. Thus, every softener should be disinfected after installation, some will require periodic disinfection during their normal life, and in a few cases, disinfection with every regeneration would be recommended."

The Type of Disinfectant for Water Softeners

There are several ways in which to proceed in order to disinfect softeners largely depending on the type of disinfectant employed. Commonly used for this purpose are sodium hypochlorite or calcium hypochlorite.

Sodium hypochlorite (household bleach) is quite frequently the choice for disinfecting a new unit. With polystyrene resins, the recommended dosage is 1.2 fluid ounces per cubic foot of resin. With nonresinous exchange materials, 0.8 fluid ounces per cubic foot is suggested. For salt-in-head or brine tank units using downflow regeneration design:

  • begin by backwashing, draining to the point where water is about 1/2 inch above the exchange resin;
  • pour in the required amount of sodium hypochlorite;
  • refill unit from the bottom by backwashing;
  • and close the unit when full and proceed with normal downflow regeneration. For upflow regeneration units the disinfectant may be added to the brine well.

When calcium hypochlorite is used as the disinfectant, the dosage should be 2 grams (approximately 0.1 oz.) per cubic foot. Calcium hypochlorite, which is 70% available chlorine, is available under such trade names as H.T.H. and Perchloron. These products, which are available in both tablet and granule forms, may be placed directly in the unit without first dissolving them. With downflow regeneration, the steps are then:

  • backwash the unit,
  • pour in the required amount of disinfectant from the top of the unit,
  • unit from bottom by backwashing, and
  • rclose unit and proceed with normal downflow regeneration. For upflow regeneration softeners, the disinfectant may be added to the brine well.

Some softener manufacturers suggest the addition of dry chlorine compounds to the salt when filling the unit as a means of providing for continuous disinfection of the softener.

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