Chlorine can be purchased in two formulations: calcium hypochlorite, which is a dry powder or tablet, and sodium hypochlorite, which is a liquid (commonly called chlorine bleach). Calcium hypochlorite dissolved in water or sodium hypochlorite is added to the water system through an injection pump. These pumps can be adjusted to add the prescribed amount of chlorine and are activated by the well pump.

Other types of chlorinators add chlorine tablets to the water supply, often at the well. They are called erosion and pellet chlorinators.

Erosion chlorinators consist of a canister to hold a supply of chlorine tablets and a chamber to allow water to flow over and dissolve the tablets. These units have the advantage of using chlorine tablets that are easy to handle and store. However, the chlorine dose they deliver tends to fluctuate greatly and is difficult to control.

Pellet Chlorinators also stand on top of the well and drop chlorine tablets directly into the well. A preset number of tablets are dropped in response to water being pumped. The well must be clear of obstructions to ensure that the tablets do not become lodged before reaching water level.