Common household bleach and purpose-manufactured liquid chlorine (sometimes known as shock) share the same active ingredient. Both sanitizers can be used to effectively treat and maintain swimming pools.
Household Liquid Bleach
Common household liquid bleach has the chemical formula NaClO as its active ingredient/sanitizer (sodium hypochlorite) and has a 6 percent concentration of sanitizer by volume.
Pool-branded liquid chlorine
The liquid chlorine found in pool stores is similar. Its active chemical agent is the same as in common bleach (NaClO), but in a higher concentration of approximately 12 percent by volume.
Granulated shock is calcium hypochlorite and has the chemical compound Ca(OH)2. It has stronger concentration of chlorine per quantity; 1 pound treats about 10,000 gallons. It is typically used on a weekly basis
Both forms of liquid sanitizer--household bleach or liquid chlorine--are effective sanitizers and, in very large quantities, can also be used for treating green water that has bloomed with algae.
It is thought that bleach will be less expensive to use. While the active ingredient in both liquid sanitizers is the same, more bleach must be used to sanitize a pool due to the lower concentration of NaClO.