Pool glossary
Pool-builder vocabulary, translated into plain language.
Anti-vortex cover
A domed or channeled drain cover that breaks suction vortices, preventing hair or limbs from being trapped at the main drain.
Balance tank
A buffer reservoir that overflow and infinity pools need: it receives the water spilling over the edge and feeds the pump, absorbing the level swings caused by swimmers.
Beach entry
A gently sloping, zero-depth entry that starts at deck level and descends like a natural shore — no steps at all.
Cartridge filter
A filter using pleated cartridges instead of sand: finer filtration, no backwash water waste, but cartridges need periodic rinsing and replacement.
Chlorine
The standard pool sanitizer: it oxidizes organic matter and keeps bacteria and algae from growing.
Coping
The ring of finished stone or masonry that caps the pool wall at the waterline — the edge your hand grabs and your eye reads as the pool's outline.
Counter-current unit
A powerful jet that produces an adjustable current to swim against — endless swimming in place, even in a 5-metre pool.
Cover pit
A recess at one end of the pool — under a bench, behind a wall or below the deck — housing the roller of an automatic slatted cover.
Deck-level overflow
An edge system where the water stands flush with the surrounding deck and continuously spills into a hidden perimeter channel, from which it is filtered and returned.
Deep end
The deepest zone of the pool, typically 1.8–2.0 m in family pools — deep enough for free swimming and treading water.
Fiberglass pool
A one-piece factory-molded basin craned into a prepared excavation — the fastest route from order to swimming.
Freeboard
The vertical distance between the water surface and the top of the pool edge — typically ~15 cm in skimmer pools, near zero in deck-level overflow pools.
Gunite / shotcrete
Concrete sprayed at high velocity onto a rebar cage, forming a monolithic shell of any shape — the technique behind most custom concrete pools.
Hydrostatic valve
A one-way valve in the pool floor that lets groundwater into the empty basin instead of letting it lift the shell out of the ground.
Infinity edge
A vanishing-edge wall lowered to a precise weir so water sheets over it into a catch basin below, visually merging the pool surface with the landscape behind.
Lap pool
A long, narrow pool built for exercise swimming — typically 12–25 m long, 2.5–4 m wide, uniformly ~1.35 m deep.
Main drain
A suction point at the pool's deepest point that pulls water from the bottom into the filter circuit and makes full draining possible.
Mosaic tile
Small-format tile (2–5 cm) mounted on mesh sheets — the format that wraps curves, radii and Roman steps without cutting.
Overflow gutter
The perimeter channel of a deck-level pool that catches the continuously overflowing water — finished as a grate or a narrow slot.
Paver
A modular deck element — porcelain, concrete or natural stone — laid on a bed or pedestals around the pool.
pH
The acidity measure of pool water; the target band is 7.2–7.4, where sanitizers work best and eyes and skin stay comfortable.
Plunge pool
A small, usually uniformly deep pool (up to ~13 m²) built for immersion rather than swimming — cooling off, soaking, cold plunges.
Pool deck
The paved area surrounding the pool — the room the pool lives in. Slip resistance, barefoot-friendly surface temperature and drainage away from the pool are its three duties.
Pool grout
The joint filler between pool tiles — in pools always a water-resistant epoxy or high-grade cementitious grout that survives permanent immersion and chemicals.
Pool heat pump
An air-source machine that moves heat from outdoor air into pool water at 4–6× the efficiency of direct electric heating.
Pool liner
A waterproof PVC membrane fitted over the pool structure — the budget-friendly waterproofing and finish in one layer.
Pool plaster
A seamless cementitious interior finish (marcite, quartz or polished aggregate) troweled over the shell.
Pool robot
An autonomous electric cleaner that drives the floor (and walls, on better models), scrubbing and filtering into its own canister.
Pool shell
The structural basin of the pool — reinforced concrete, sprayed gunite, factory fiberglass or panel construction — that carries water and ground pressure.
Porcelain pool tile
Fully vitrified ceramic tile with near-zero water absorption — frost-proof, colorfast and chemically inert, the most durable pool interior.
Return inlet
The nozzle that pushes filtered water back into the pool, angled to set up a slow rotation that carries debris toward the skimmers.
Roman steps
Semicircular steps flowing out of the pool wall in concentric arcs — the classical entry borrowed from Roman baths.
Salt water system
An electrolysis cell that generates chlorine on site from mildly salty water (~0.4% — a tenth of seawater).
Sand filter
The classic pool filter: water passes through a bed of sand (or glass media) that traps particles, cleaned by backwashing.
Shallow end
The standing-depth zone of the pool, typically 1.0–1.2 m — where children play, adults wade and steps arrive.
Shock treatment
A deliberate short-term overdose of sanitizer that oxidizes contaminants after heavy use, storms or the first signs of algae.
Skimmer
A wall-mounted unit that draws the top few centimetres of pool water into the filtration circuit, harvesting floating debris, dust and oils before they sink.
Slatted cover
An automatic cover of rigid PVC or polycarbonate slats that rolls out over the water at the push of a button, from a pit or bench.
Solar cover
A floating bubble-foil blanket that warms the water a few degrees and, more importantly, stops evaporation — the pool's biggest heat loss.
Swim spa
A compact heated basin (4–6 m) with a powerful counter-current for swimming in place, often doubling as a hot tub.
Tanning ledge
A large flat shelf 10–40 cm below the surface — usually 15 cm — sized for in-water loungers, toddlers and lounging.
Travertine
A porous natural limestone in warm cream-to-walnut tones — the classic Mediterranean coping and deck stone.
Turnover rate
The time the circulation system needs to pass the pool's entire volume through the filter once — typically 4–6 hours for private pools.
Waterline tile
The band of tile at the water's surface where scale, sunscreen and grime concentrate — tiled even in otherwise plastered pools because tile scrubs clean.
Winterizing
Preparing a pool for freezing weather: lowering the water below the skimmers, blowing out pipes, adding winter chemicals and covering.
Your pool is a few clicks away
Open the designer and see your garden's pool in 3D — free, right now.
Start designing — it's freeFree · no signup · runs in your browser