Chlorine is the most common disinfectant used by pool owners. Pool chlorine is available in tablets, grains and sticks, and is the most affordable water treatment option available to pool owners.
Chlorine is an effective sanitizer and oxidizer. Chlorine kills bacteria and removes additional organisms from the water such as body sweat. It also inhibits and kills algae.
Depending on the type of chlorine, some can be dispensed through the skimmer. Other types are added to the water through a chlorinator or chlorine dispenser. Chlorine generators work differently than a dispenser, because they actually generate chlorine from the salt in a pool's water.
Chlorine also has drawbacks. Some people don't like its obtrusive smell, or are put off by its effect on skin, eyes, hair and clothing.
Chlorine also rapidly depletes when exposed to the sun's rays. For this reason, many manufacturers produce stabilized chlorine which contains a stabilizer (cyanuric acid) that shields the chlorine from the sun so it depletes less rapidly.
Unstabilized chlorine requires the pool owner to add a stabilizer to the water separately. Additional stabilizer is normally put in the water at the beginning of the season and during water replenishment. If you use dichlor or trichlor chlorine, then chances are it already has a stabilizer included.
Super-chlorinators or shocks are also part of a chlorine-based regimen. Shock treatments are normally done when the pool is opened. Shocks are also used when the water requires extra disinfection to eliminate algae or other bacteria.