The long-term cost associated with manually added liquid chlorine bleach consists mainly of the cost of the liquid chlorine bleach itself. That is why it is generally considered to be the most cost-effective (as well as the most chemically effective) way to chlorinate and sanitize residential swimming pools.
Liquid chlorine bleach is readily available at nearly all swimming pool supply stores in reusable plastic jugs that range from one gallon to 2.5 gallons. The use of reusable jugs dramatically reduces the cost of the liquid chlorine bleach. In fact, the cost of the plastic jug is usually more than the cost of the liquid chlorine bleach.
The actual long-term cost of liquid chlorine bleach (or any other method of chlorination) for a given swimming pools will depend on the pool size and chlorine demand. To illustrate a generalized long-term cost for purposes of cost comparison with other methods, such as chlorine tablets or salt/chlorine generators, a pool size of 20,000 gallons and a time frame of ten years will be assumed. It will be assumed the pool is initially filled and a pH of 7.6 is established with a 3.0 part per million chlorine (ppm) concentration. Assuming some chlorine demand occurs over a 24-hour period and the chlorine concentration drops to 1.5 ppm, the amount of chlorine needed to raise the chlorine back to 3.0 ppm can be determined using a pool calculator. (8) From the assumptions used in this example it will take 37 ounces of 10% liquid chlorine bleach to raise the chlorine level back to 3.0 ppm in a 20,000 gallon pool. Assuming this change occurs daily, the amount of liquid chlorine bleach needed to be added each week will be 7 times 37 ounces or 259 ounces per week or about 2 gallons per week. Over a one-year period 104 gallons of 10% liquid chlorine bleach will be needed. At a price of approximately$1.93 per gallon (based on reusable jugs) a ten-year cost for liquid chlorine bleach is approximately $2,030.
The cost example shown is for comparison purposes to other methods of swimming pool sanitization such as chlorine tablets or salt/chlorine generators. Actual cost will vary depending on water quality, weather, sunlight exposure, contaminants and chlorine demand. An acid or base additive will be needed periodically for pH control. The amount of acid or base required with the use of liquid chlorine bleach varies with many factors and is not calculated for this example. However, the cost of acid/base additives generally is minimal and not significant when liquid chlorine bleach is regularly used.
Liquid Chlorine Bleach: Other Pool Chemicals Needed Maintenance Requirements