If water is temporarily hard, however, it may be softened by being boiled, then allowed to stand until the lime settles. The top water is afterward drawn off. Boiling water to soften it is without doubt the best method if it softens the water sufficiently, since no harmful chemicals are left in the water to injure fabrics.
Either temporarily or permanently hard water may be softened by adding lime or washing-soda to the water, then allowing it to stand in open kegs for several days before its use. The water should then be drawn from the top. If the water is boiled after the addition of the softening agent, the time for standing may be considerably lessened. Neither of the two processes just described is much in use in the household, since the time consumed by them is often considered unwarranted. The more common method is to add washing-soda, lye, borax, or ammonia at the time of washing. The addition of one of those substances at that time prevents the action of the lime on the soap. A good suds may thus quickly be obtained, but it does not rid the water of the lime-soap curd which forms and which, in part at least, becomes entangled in the pores of the cloth. The entangled curd has a weakening action on the fabric and gives it a close, filled-in appearance.
The only satisfactory method of getting rid of iron is to add washing-soda to the water, then allowing the water to settle for five or six days before using it. The top water is afterward drawn off.
Water may be softened by any of the following methods:
1. For each gallon of water, use 2 tablespoons of a solution made by dissolving 1 pound of washing-soda in 1 quart of boiling water. The solution should be bottled and kept on hand, as it is a useful cleansing agent, or detergent.
2. For each gallon of water use 1/4 tablespoon of lye dissolved in 1 cup of water.
3. For each gallon of water use 1 tablespoon of borax dissolved in 1 cup of water.
If water is very hard, increase the amount of alkali used.