Algae spores constantly enter the pool, brought in by wind or rain and it multiplies rapidly on warm, sunny days. Containing chlorophyll, algae utilizes photosynthesis to grow. A lack of proper circulation, filtration and sanitation may be the primary cause of the algae. 

The process of running water through a filter in the opposite direction to flush the filter of debris. It will free up the filter to be less restricted so the water can pass through the filter more efficiently, collecting more debris.

A chemical compound that is used as a disinfectant to destroy bacteria and algae in swimming pools and spas.

Outward force created by an object in circular motion. Centrifugal force is created by water pumps to move water.

Any type of chlorine compound used as a disinfectant in swimming pool and hot tub water or to kill, destroy or control bacteria and algae. 

The cap stone on the edge of a pool or spa mounted on the bond beam.

 A valve that changes the direction or redirects the flow of water.

The water discharging from a pipe or equipment.

Removes particles from water by recirculating the water through a porous substance (a filter medium or element). Three types of filters used in pools and spas are sand, cartridge and D.E. (diatomaceous earth).

 Also known as the filter cycle, it is the time between cleanings or the the total running time of the system.

Device used to measure the rate of water passing through a given pipe, expressed in gallons per minute (gpm).

The volume of water passing, expressed in gallons per minute (gpm).

A measuring device used to measure pressure on filtration systems.

A plumbing fitting installed on the suction side of the pump in pools, spas and hot tubs for circulation and filtration. It is usually located in the deepest part of the pool, hot tub or hot tub. 

A measure of the level of acidity or alkalinity of water on a scale ranging from 0-15.  The ideal range for pH in swimming pools is typically 7.4 to 7.6.

A combination of white cement, aggregates, and additives that covers the shell of a pool or spa.

A device that registers the pressure in a water or air system, expressed in pounds per square inch (psi).

The volume of liquid a pump can move during a specified period of time, listed in gallons per minute or gpm.

The process of adding large amounts of an oxidizing chemical to the water to destroy ammonia and nitrogen compounds.

Refers to a process in which compressed air forces mortar or concrete through a hoseand nozzle onto a surface at a high velocity.

A part of the circulation system that removes debris from the surface of the water.

Cloudiness

Amount of time required for a system to filter 100 percent of the pool water.

A device that controls the flow of water. Three common styles of valves are wafer, ball, and gate.