How Does a Salt Water Pool System Work?

How a Salt System Operates

Salt systems have three main components.

Salt

The first component is plain old salt.  You have to have a minimum level of about 3000 parts per million of salt in the pool water.  Salt makes the water conductive so that the electricity can pass between the plates in the cell.  If the salt level goes too low, then the chlorine production simply stops.  Salt is also the raw material from which the chlorine is produced.

Control Box

The control unit is a device that sends power to the salt cell.  The unit controls how much chlorine is produced by regulating how long the power is applied to the cell.  If you turn the control knob way down, then the unit might apply power to the cell only 25% of the time, thereby producing less chlorine.  If you turn the control knob up, then the unit would apply power to the cell for a longer period of time.  The amount of power applied to the cell does not increase or decrease.

The control unit will often sense the level of salt in the pool and indicate the need to add more salt.

Self cleaning units have a feature built into the unit that reverses the polarity of the voltage through the cell in order to clean any scale buildup off of the cell plates.

Salt Cell

The salt cell is a series of plates with opposite charges in a cell. As the water passes between the plates, electrolysis takes place, releasing the chlorine in the salt.