In-line pool chlorinators are designed to be plumbed into the piping of your equipment system after the heater. They should be the last major component in the system before the water returns to your swimming pool. If your pool equipment system has a heater, be sure to install a check valve between the pool chlorinator and the pool heater. In-line chlorinators are available in 1.5 inch or 2 inch plumbing options and above ground pool models from the drop down menu below.