The chlorine in household bleach can be used to sanitize swimming pools, though it is generally less concentrated than chlorine designed for pool use. Bleach additives can harm the pool, so a generic household bleach works best.
In addition to the liquid chlorine found in household bleach or in bottles sold for pool sanitization, chlorine can be purchased in tablet or granular form. The tablets can be placed in a floating chlorinator or in the feeding line of the pool equipment. The granular form is commonly sold as a shock treatment.
An alternative to purchasing chlorine is to purchase salt. Salt water pools require a separate system to convert the salt into chlorine for sanitization.