If you’ve been shopping around for a swimming pool chlorinator, you’ve probably noticed that you have two options: inline and offline chlorinators. They both function the same and cost about the same
The main difference lies in how they are installed. The inline chlorinator is installed directly into the piping that’s connected to your pump and filter system. The offline chlorinator is installed on the side of the system and connected with a tube. You’ll probably find that certain pool chlorinators can be adapted to work either way.
See the diagram below to better understand the differences between inline and offline chlorinators: