These inline or offline units from Hayward allow you to safely and efficiently put chlorine in your pool.  They allow you to put in about 10-15 tablets and adjust the output to meet your pools chlorine demand.  This gives you the ability to run the unit without having to monitor daily your chlorine usage.
With this unit you could run the thing for up to three weeks without having to refill the unit.  Talk to our staff about which option is best for your swimming pool.