The Perfect Pool Blog

Zodiac's In-Depth Resource for All Things Pool.

Get to Know Your Pool

Get to Know Your Pool

Is “shocking your pool” as dramatic as it sounds? And what is a “baja shelf?”

If only you knew the meaning of half the words that your pool builder or technician use in everyday conversation.

Here’s our quick-glance glossary of pool terminology you can master and comprehend. The next time you talk with an expert, you too can calmly insert them into your conversation – while also understanding how your own swimming pool works.

Backwash. This is a process designed to lower pressure, improve water flow and clean the filter medium by temporarily reversing the flow of water to flush out contaminants and debris — sending dirt and used water to waste.

Baja shelf. Also known as a sun shelf or tanning shelf, this is a wide shallow step in the pool where people can sit immersed in about eight to 16 inches of water. It’s popular for small children as well as people who want to enjoy the sun while staying cool in the water.

Chemical feeder. This equipment automatically releases chemicals into the pool at a regular rate, such as chlorine or bromine as well as pH-balancing chemicals.

Coping. The finished edge or lip of the pool.

D.E. or Diatomaceous earth. This filter medium is porous earth, one type that’s used to clean and filter pool water.

Flocculant. This chemical is used to aggregate tiny suspended particles together into a larger floc, which can then be caught in the filter more successfully than the individual particles

Gunite. Technically, a concrete pool. Gunite is made by mixing cement and sand together and sprayed onto the surface of the pool. Afterwards, plaster can be applied on top of the gunite as a finish.

Gutter. A trough along the edge of the pool that collects debris, oil, and other items that float on water.

Hand skimmer. A giant net attached to a long pole used to remove floating debris from the pool’s surface, such as leaves and insects.

Main drain. This drain is located in the deepest part of the swimming pool or hot tub and installed on the suction side of the pump. It does not actually drain the water out but rather to the pump for circulation and filtration.

Negative edge. Also known as an infinity edge or vanishing edge, this design feature makes the eye believe the pool water is running over the edge.

Pool pump. Equipment that pumps pool water through for filtering, heating, and circulating. It consists of the motor, impeller, and lint trap. It pushes water through the filtration system and pumps it back into the pool.

Shocking. This method adds a large dose of chlorine or other type of oxidizing chemical to kill compounds created by human waste such as oils, sweat, skin, or hair, which can accumulate over time and decrease the effectiveness of the chemical cleaning agents in your pool. A separate product, usually marketed as “shock,” can be used to clear the pool on a regular basis.

Skimmer basket. A removable basket or strainer connected to the skimmer, the mechanism connected to the pump suction line, that traps toys and other larger debris without restricting water flow. The skimmer is designed to draw water without restricting flow as well.

Zero-entry. Also known as a beach-entry, this design element is a slow incline into the pool, like a ramp. It’s popular for older people who don’t like steps, small children, and people with wheelchairs. It’s also great for people who would rather lie in a few inches of water.

About This Blog

Includes all the latest information, tips, and expert advice from Zodiac Pool Systems, Inc. on owning the healthiest, safest, most enjoyable pool possible.


Zodiac is a leading global manufacturer of differentiated pool and spa products. With our rich heritage of innovation excellence, we develop some of the world's leading products that afford our customers a better life.


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