Pool & Spa Glossary: A-L

Acid Demand
The proper amount of acid -- a pH and total alkalinity decreaser -- required to reach correct levels. The amount of acid needed is determined by conducting an <b>acid demand</b> test.

Algae
Algae are microscopic plantlike organisms that contain chlorophyll. They are nourished by carbon dioxide and rely on sunlight to carry out photosynthesis. Algae grow in colonies. While more than 21,000 species of algae exist, the types most commonly found in swimming pools are black algae, blue-green algae, green algae and mustard algae (yum!).

What is Backwash or Backwashing?
What is backwash? Learn the definition of backwash and the backwashing procedure as it pertains to swimming pool maintenance.

Chlorine
A disinfectant added to swimming pool or spa water to destroy and maintain an environment that will prevent bacteria and algae to grow and thrive. Chlorine also is used to oidize unwanted organic and nitrogen waste.

Coping
What is Pool Coping? The definition of coping is the cap on the edge of a swimming pool or spa, which is mounted on the bond beam

What is a Fiberglass Pool?
Basically, a fiberglass pool is made of a fiberglass or acrylic shell that is placed in a hole in the ground. Find out more about this type of swimming pool and why you might want one.

Freeform Pool
Definition: A swimming pool that is designed in a naturalistic style and shape. Freeform pools often have rock and waterfall features and are designed to resemble a natural pond, lake or oasis.

Hot Tub
Like a spa, a hot tub has built-in jets to provide warmth, relaxation and a massage-effect on people's muscles and joints. They both are used for therapeutic reasons and socialization. The difference, however, lies in the material. Hot tubs are made from wood, usually redwood, cedar, cypress, teak or a composite.

Lap Pool
Definition: A swimming pool used for fitness and health purposes. Lap pools are usually long and narrow, often more than 50 feet in length. Typically, lap pools are a rectangular shape.