The Complete Pool Glossary

A motorized device attached to a plumbing valve that automatically turns the valve to direct water flow, controlled by the automation system.

A chemical designed specifically to kill or prevent the growth of algae.

A measure of the water's ability to resist changes in pH. Proper alkalinity acts as a buffer to keep pH stable.

A luxury pool where the entire interior surface is covered in tile, rather than plaster or aggregate.

A powerful sanitation system that combines UV light and ozone to create hydroxyl radicals, highly effective at destroying contaminants.

A device that automatically adds water to the pool when the level drops below a certain point due to evaporation or splashing.

A motorized safety cover that rolls out over the pool at the push of a button, running in tracks along the pool edges.

A centralized control panel that allows the homeowner to operate the pump, heater, lights, and water features via a smartphone app.

The material (usually gravel or clean dirt) used to fill the excavated space around the outside of the pool shell after it is built.

A large, shallow area within the pool (typically 6-12 inches deep) designed for lounging, often featuring ledge loungers or umbrellas. Also known as a tanning ledge or sun shelf.

A chemical (sodium bicarbonate) used to raise the total alkalinity of pool water.

A sloping entry into the pool that mimics a natural beach, gradually transitioning from the deck to the water without steps.

A type of flagstone known for its blue-gray color, commonly used for coping and patios.

The continuous, reinforced concrete ring around the top perimeter of the pool shell that provides structural integrity and supports the coping.

An electrical safety requirement that connects all metal components around the pool (rebar, ladders, lights) with a copper wire to prevent electrical shock.

An additional pump used specifically to power a pressure-side pool cleaner or high-flow water features.

Standard concrete with a textured surface created by dragging a broom across it before it cures, providing slip resistance.

A small water feature typically installed on a Baja shelf or shallow area that shoots a bubbling stream of water upward.

Coping stones with a rounded, semi-circular edge facing the pool.

A chemical used to raise the calcium hardness of pool water.

A measure of the dissolved calcium in the water. Too low can cause the water to corrode plaster; too high can cause scaling.

A style of coping where the concrete deck is poured to extend slightly over the edge of the pool, eliminating the need for separate coping stones.

A type of filter that uses pleated paper or polyester cartridges to trap debris, offering finer filtration than sand.

The hidden trough or lower pool that collects the water flowing over an infinity edge so it can be pumped back into the main pool.

A common and versatile tile option for the waterline, available in many colors and patterns.

The official document issued by the municipality after the final inspection, certifying the pool is safe and legal to use.

A plumbing valve that allows water to flow in only one direction, preventing backflow.

A device, often combined with a heat pump, used to cool the pool water during extremely hot weather.

Another term for combined chlorine; the irritating byproducts of chlorine reacting with sweat, oils, or urine.

The most common chemical used to sanitize pool water, destroying bacteria and algae.

A device plumbed into the return line that automatically dispenses chlorine from tablets into the pool water.

A chemical that causes microscopic particles in the water to clump together so they can be caught by the filter, clearing cloudy water.

Another term for a plunge pool or spool; a small pool designed for socializing and relaxing.

Chlorine that has already reacted with contaminants and is no longer effective, often causing the strong 'chlorine smell' and eye irritation.

The process of mechanically compressing backfill material to prevent future settling under the pool deck.

Another term for Cyanuric Acid.

A local agency that oversees soil erosion and sediment control during construction, often requiring separate permits and inspections.

A temporary pad of large stone installed at the street to prevent construction vehicles from tracking mud onto public roads.

A textured concrete coating designed to significantly lower the surface temperature of the pool deck.

The cap or edging that finishes the top edge of the pool wall, separating the pool structure from the surrounding deck or patio.

The deterioration of metal pool components or plaster surfaces caused by water with low pH or low calcium hardness.

The chemical process by which concrete hardens and gains strength over time, requiring moisture and proper temperatures.

A chemical added to outdoor pools to protect chlorine from being rapidly destroyed by the sun's UV rays. Also known as stabilizer or conditioner.

The most effective type of pool filter, using a fine powder made from fossilized diatoms to trap microscopic particles.

A water feature installed in the pool deck that shoots a narrow stream of water into the pool.

A pool where the water level is exactly even with the surrounding deck, often utilizing a perimeter overflow system.

A popular brand of quartz pool finish.

A plumbing valve used to direct water flow between different pipes, such as switching between the pool and the spa.

A pool built with specific depth and slope requirements to safely accommodate a diving board.

A safety device required by many codes that sounds an alert when a door leading from the house to the pool area is opened.

Coping stones with a square edge that drops down vertically into the pool, offering a modern, clean look.

A designated area of a property where someone else (like a utility company) has the right to access or restrict building.

The height of the pool relative to the house and surrounding yard, critical for proper drainage and aesthetics.

A pipe connecting the skimmer to the main drain or a wall fitting, ensuring the skimmer pump doesn't run dry if the water level drops.

The process of digging and removing earth to create the hole for the pool shell.

A flexible joint placed between the pool coping and the concrete deck to allow for independent movement and prevent cracking.

A premium pool finish that blends cement with small pebbles, glass beads, or quartz, which are then exposed by washing away the top layer of cement.

A concrete deck finish where the top layer of cement is washed away to reveal the stones or gravel within.

The vessel that removes dirt, debris, and microscopic particles from the pool water.

The last review by a municipal inspector to ensure the completed pool meets all safety, electrical, and building codes before it can be used.

A feature that combines a gas fire element with a water spillover in the same fixture.

A decorative bowl placed on a pool wall or pillar that contains a gas-powered fire feature.

A dedicated area near the pool for a contained fire, often built into the patio or a sunken seating area.

A generic term for flat slabs of natural stone used for paving.

A chemical that causes suspended particles to clump together and sink to the bottom of the pool, where they must be vacuumed out.

A hot tub built at the same elevation as the main pool, separated by a dividing wall.

The use of wood or other materials to create a mold that holds concrete in place until it sets, often used for the bond beam or raised walls.

The active, available chlorine in the water that is ready to sanitize contaminants.

A pool design characterized by natural, flowing curves and irregular shapes, often designed to mimic a natural pond or lagoon.

A trench filled with gravel and a perforated pipe used to redirect surface water and groundwater away from the pool area.

A heater powered by natural gas or propane, capable of heating the water quickly regardless of air temperature.

The smooth, durable, and often colored top layer of a fiberglass pool shell.

A pool design characterized by straight lines, sharp angles, and symmetrical shapes, such as rectangles or L-shapes.

A safety device required on pool electrical circuits that instantly cuts power if it detects a ground fault, preventing electrocution.

A premium waterline or full-pool tile option known for its vibrant colors, translucency, and durability.

The process of leveling or sloping the land around the pool to ensure water drains away from the pool and the house.

A rectangular pool with modified, truncated corners, offering a classic, elegant look.

A cave-like structure built into the pool, often featuring a waterfall cascading over the entrance and seating inside.

An electrical safety requirement that connects the pool equipment to the earth to safely direct any stray electrical current away from the pool.

A mixture of cement, sand, and water applied through a pressure hose, producing a dense, hard layer of concrete used in building custom pools.

An energy-efficient heater that extracts heat from the surrounding air and transfers it to the pool water.

A device used to warm the pool water, extending the swimming season.

Permission required from a Homeowners Association before building a pool, often involving strict design and material guidelines.

A popular brand of polished aggregate pool finish.

A valve installed in the main drain at the bottom of the pool that allows groundwater to enter the pool if the external water pressure exceeds the internal pressure, preventing the pool shell from floating or cracking.

The percentage of a property covered by materials that do not absorb water, such as the house, driveway, and pool deck. Many towns strictly limit this.

A network of pop-up nozzles built into the pool floor that systematically sweep dirt and debris toward the main drain for removal.

Older, less efficient pool lights that produce a warm white glow, now largely replaced by LEDs.

A design feature where water flows over one or more edges of the pool, creating a visual effect of water with no boundary. Also known as a vanishing edge or negative edge.

A classic freeform pool shape resembling a kidney bean, popular for its natural look and clear separation of shallow and deep ends.

A high-end water feature that produces a perfectly clear, glass-like arc of water, often illuminated with LED lights.

A formula used to determine if pool water is balanced, corrosive, or scale-forming based on pH, alkalinity, calcium hardness, temperature, and cyanuric acid.

A long, narrow pool designed specifically for swimming laps for exercise.

Energy-efficient pool lights capable of producing bright, customizable colors and light shows.

Perfectly horizontal; critical for the bond beam to ensure the water line appears even around the entire pool.

A natural stone often used for pool coping and decking, valued for its light color and cool temperature.

The suction outlet located at the deepest part of the pool, used to circulate water from the bottom.

A pipe with multiple ports used to distribute water to several different lines, often used for in-floor cleaning systems or water features.

Another term for standard white pool plaster.

A flexible, waterproof sealant used to fill the expansion joint between the coping and the deck.

Small tiles arranged in a pattern or picture, often used as decorative accents on the pool floor or steps.

A strong acid commonly used to lower the pH and alkalinity of pool water.

Another term for an Infinity Edge.

The housing built into the pool wall that holds the light fixture.

Digging deeper or wider than the final pool dimensions, often required to remove unsuitable soil or to provide working room.

A pipe installed near the top of the pool to drain excess water during heavy rain, preventing the pool from overflowing.

A supplemental sanitation system that injects ozone gas into the water to oxidize contaminants and reduce the need for chlorine.

Individual blocks of concrete, brick, or stone used to create the pool deck or patio.

A variation of Pebble Tec that uses finely crushed pebbles for the smoothest aggregate finish.

A variation of Pebble Tec that uses smaller pebbles for a smoother texture.

A popular brand of exposed aggregate pool finish known for its durability and natural appearance.

A design where water overflows all edges of the pool simultaneously into a hidden slot, creating a mirror-like surface flush with the deck.

Official approval from a local government agency required before beginning pool construction.

A measure of how acidic or basic the pool water is, on a scale of 0 to 14. The ideal range for a pool is 7.4 to 7.6.

The traditional interior finish for concrete pools, made of a mixture of white cement and marble dust.

A pool designed with shallow water on both ends and a slightly deeper section in the middle, ideal for water sports like volleyball.

A detailed drawing of the property showing the proposed location of the pool, deck, equipment, and setbacks, required for permit applications.

Perfectly vertical; an important measurement when building raised walls or setting tile.

The point during construction where PVC pipes are brought up from the ground to connect to the pool equipment pad.

A small, relatively deep pool designed for wading and cooling off rather than swimming or playing.

A pool finish where the aggregate material is polished smooth after application, creating a luxurious, marble-like surface.

A barrier required by law around the pool area to prevent unauthorized access, typically required to be at least 48 inches high with self-closing, self-latching gates.

A dense, durable tile option often used for the waterline or pool interior.

A pool vacuum powered by water pressure from the return line or a dedicated booster pump, pushing debris into an attached bag.

The heart of the pool's circulation system, an electric motor that pulls water from the pool and pushes it through the filter and heater.

A pool finish that blends cement with crushed quartz, offering a smoother texture than pebble finishes and vibrant color options.

The curve of a pool wall or corner, measured from a central point.

A hot tub built adjacent to the pool but elevated above the pool's water level, often featuring a spillover into the main pool.

Steel reinforcing bar used as a framework to provide tensile strength to the concrete shell of a gunite pool.

A structural wall built to hold back soil, often necessary when building a pool on a sloped property.

The fitting in the pool wall where filtered, heated, and treated water is pushed back into the pool.

An independent, electric-powered vacuum that roams the pool floor and walls to collect debris in its own filter bag.

A rectangular pool with semi-circular ends, inspired by ancient Roman baths.

A strong, tensioned cover anchored to the deck that can support the weight of a person or pet, preventing accidental drownings during the off-season.

The component of a saltwater chlorinator where the electrolysis takes place.

A device that uses electrolysis to convert dissolved salt in the pool water into pure chlorine, eliminating the need to add liquid or tablet chlorine.

A type of filter that uses special pool sand to trap debris as water passes through it.

White, crusty deposits of calcium carbonate that form on pool surfaces and equipment when calcium hardness or pH is too high.

A decorative wall-mounted fixture that pours water into the pool.

A spout or slot in a raised wall that allows water to flow into the pool, often used in geometric or modern designs.

An underground pit filled with gravel designed to capture and slowly absorb stormwater runoff, often required for pool permits.

The minimum required distance between the pool (or pool equipment) and the property lines, house, or other structures.

A type of waterfall that produces a clear, arc-like sheet of water dropping into the pool.

The process of adding a massive dose of chlorine or non-chlorine oxidizer to the pool to destroy chloramines and clear cloudy water.

Similar to gunite, but the concrete is mixed with water before being pumped through the hose, rather than mixing at the nozzle.

A temporary barrier installed around the construction site to prevent soil from washing onto neighboring properties or into waterways.

An older style of pool pump that operates at only one high speed, consuming more energy.

A surface-level opening built into the pool wall that draws in water and floating debris before it can sink.

A chemical (sodium carbonate) used to raise the pH of pool water.

The ability of the soil to support the weight of the pool structure without excessive settling.

A floating cover resembling bubble wrap that helps retain heat and reduce evaporation.

A system that pumps pool water through solar panels on a roof to be heated by the sun.

The section of a raised spa where water cascades down into the main pool.

A hybrid between a spa and a pool; larger than a typical hot tub but smaller than a standard pool, often equipped with strong jets for resistance swimming.

Another term for a play pool.

Having corners that are exactly 90 degrees, important for geometric pool designs.

Another term for Cyanuric Acid.

Concrete that is patterned and textured to resemble brick, slate, flagstone, or wood.

Natural stone cut into tiles, offering a rustic or elegant look for the waterline or raised walls.

Engineering plans required by many municipalities to show how rain runoff from the new pool and deck will be handled to prevent flooding.

A pool vacuum that connects to the skimmer or a dedicated suction line, powered by the main pool pump.

Another term for a Baja Shelf or Tanning Ledge.

A dry lounge area built adjacent to the pool but at a lower elevation, often placing seated guests at eye level with swimmers.

The additional pressure exerted on a pool wall by the weight of nearby structures, slopes, or heavy equipment.

A seating area inside the pool featuring underwater bar stools facing a counter or sunken kitchen area.

Another term for a Baja Shelf; a shallow lounging area in the pool.

A measure of all the substances dissolved in the pool water, including salt, minerals, and chemical residues.

A survey showing the elevation contours of the property, often required for complex sites or stormwater management plans.

The sum of free chlorine and combined chlorine in the water.

An electrical device that reduces high voltage from the house to the low voltage required for safe pool lighting.

A type of limestone popular for pool decks due to its elegant look and tendency to stay cool underfoot.

The amount of time it takes for the pool pump to circulate the entire volume of water in the pool through the filter system.

A supplemental sanitation system that passes water through a chamber with UV light to destroy bacteria and algae.

Another term for an Infinity Edge.

An energy-efficient pool pump that can operate at different speeds, saving significant electricity compared to single-speed models.

Refers to main drain covers that meet the safety standards of the Virginia Graeme Baker Pool and Spa Safety Act to prevent entrapment.

A custom-made sheet of vinyl that forms the waterproof interior surface of a vinyl liner pool.

A water feature where water drops from an elevated position into the pool, often built with natural or artificial rock.

The band of tile installed around the perimeter of the pool just below the coping, designed to hide the water ring and make cleaning easier.

The application of specialized materials to prevent water from penetrating the pool shell or raised walls.

A small opening left in the pool shell during construction to allow groundwater to escape before the interior finish is applied.

A solid or mesh tarp used to cover the pool during the off-season to keep out debris.

Another term for a Beach Entry.

Local laws that dictate how property can be used and where structures, including pools, can be placed.