"COMPOOL" CONTROL SYSTEM: Optional and fairly expensive, yet a highly recommended component. Basically, an up-dated and enhanced version of the time clock. "COMPOOL," a division of PAC FAB, INC, offers a system to mount in your house that will control circulation (the pump) and numerous other functions. In addition to controlling equipment and components, the "COMPOOL" Control System also shows numerous displays, including current chemical readings. You can literally receive pertinent information about your pool from inside the confines and comfort of your own home. If you purchase a "COMPOOL" Control System, as you should, have your pool professionals install it, program it, and give you a detailed orientation on all the functions. Aside from your poolmanul.com subsription, a "COMPOOL" Control System is the wisest purchase to enhance your pool ownership experience.