Return jetsOpenings in the wall below the water. They push filtered water back into the pool. Aimed well, they set the water circling toward the skimmer.
Shallow endThe shallow end, where the water is shallow enough to stand.
Deep endThe deepest part of the pool, where the bottom slopes down.
SkimmerAn opening in the wall at the waterline. It draws surface water over a floating flap into a leaf basket, catching leaves and debris.
PumpIt draws water from the skimmer and main drain. It pushes the water through the filter and back to the pool. A basket in it catches leaves and hair.
The pool: 6 3
CopingThe cap along the top edge of the pool wall. It sits between the water and the deck.
StepsThe steps, leading down into the shallow end.
LadderThe ladder, for climbing in and out at the deep end.
Where the water goes: 3 1
Main drainIt sits at the bottom of the deep end. It draws water from the bottom of the pool to the pump.
The equipment: 3 2
FilterIt traps dirt as the water passes through. It may be a sand, cartridge or diatomaceous earth filter.
HeaterThe heater, which warms the water before it returns to the pool. Heat pumps, gas and solar heaters are all used.
How this list was compiled: Read 2026-09-28. (1) Wikipedia, Swimming pool sanitation, https://en.wikipedia.org/wiki/Swimming_pool_sanitation : an electric pump recirculates the water, forcing it through a filter (sand, diatomaceous earth or cartridge) and back to the pool; pumps have a small basket for leaves and hair; skimmers draw water through an aperture in the wall over a floating hinged weir into a basket, with a lid in the deck; the main drain at the bottom supplies part of the flow; filtered water returns through return jets below the surface, whose flow sets the surface circulating past the skimmer; pool heaters (heat pump, gas, electric, solar). (2) Wikipedia, Swimming pool, https://en.wikipedia.org/wiki/Swimming_pool : pools slope to a deep end; steps and ladders; beach entries for gradual access; chlorinated or salt water; pumps and sand filters. Licence: own work
The drawing: Drawn for this site by script, 2026-09-28. Own work, nothing traced. Licence: own work
How it works
These are the parts of a pool on an in-ground swimming pool cut through lengthways, with the equipment pad that keeps the water clean. Start with the 6 main parts.
Read the full guide
The pool
The deck surrounds the pool, and the coping caps the top of its wall. Steps lead down into the shallow end; the floor slopes to the deep end, where a ladder gives a way out.
Keeping it clean
Water leaves through the skimmer at the waterline and the main drain on the floor. The pump pushes it through the filter and heater, and the return jets send it back into the pool, setting the surface circling toward the skimmer.
Empty the skimmer basket and the pump basket often: leaves caught there slow the flow to the filter.
Questions and answers
What does a pool skimmer do?
It draws water from the surface through an opening in the pool wall, over a floating flap and into a basket that catches leaves and debris before the water reaches the pump.
What are return jets in a pool?
Openings in the wall below the water where filtered water comes back in. Aimed well, they keep the surface water circling toward the skimmer.
What is the main drain for?
It draws water from the bottom of the pool, so the pump pulls from the floor as well as the surface.