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Pool Plumbing Diagram & Layout Schematic Examples

Pool Plumbing Diagram & Layout Schematic Examples
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A swimming pool uses a complex plumbing network to circulate and clean the water. With most pool plumbing components hidden behind walls and underneath the floor, most people have poor knowledge about how a pool works. Most pool owners can’t perform basic pool maintenance despite the savings it can bring.

Studying a swimming pool plumbing diagram can improve your knowledge and make it easy to understand the basics. Following the water route is the easiest way to understand the swimming pool lines. A spa combination plumbing diagram is more complex than a basic pool and spa-only plumber diagram.

Why Is Pool Plumbing Important?

Often overlooked, the plumbing network in a swimming pool or spa combo is quickly forgotten until it malfunctions. Although largely ignored, basic pool plumbing keeps the water clean, sanitary, and safe.

The plumbing in a swimming pool or spa combination continuously cycles the water through the filter to remove dirt and debris. Besides keeping the water clean to let you enjoy the swim, the plumbing in a shared pool maintains an optimal water level. Too much or inadequate water in the pool can damage the expensive pool equipment and saddle you with expensive repair bills. Likewise, leaky plumbing can lead to huge water and heating bills each month.

Pool Plumbing Diagram Types

A swimming pool diagram shows how the various components of your swimming pool’s filtration network are connected. It’s a schematic representation detailing how the pool pump, filter, heating, and sanitization equipment interact. Both above ground pool plumbing diagram and in-ground diagram designs can look similar, so make sure you look carefully.

The primary goal of a plumbing pool diagram is to offer insights into the filtration concept. It doesn’t delve into the exact pipe layouts – you can’t tell exactly where the pipes or valves are located from a pool plumbing diagram.

pool plumbing diagram infographic

Filtration Diagram

A filtration diagram shows the hydraulic design of a swimming pool. It helps visualize the water’s route when leaving and reentering the pool while showing the correct position of the valves and non-return valves. It’s an accurate representation of the filtration equipment in the pool.

A filtration diagram shows an accurate placement of the pipes in the filtration network and how they’re connected. It shows the line and valve connections between the pool and the pool room. You can tell the location of the filter, pH control, disinfection device, valves, and pool heater from an inground pool diagram.

Pool Connection Schematic

The pool connection schematic explains the water’s path through the filtration apparatus to help you understand how a swimming pool operates. It shows the location of various swimming pool equipment such as filter, heating, and disinfection. A pool connection schematic doesn’t show the calibrated pool equipment and is used in a pool with a skimmer but not an overflow pool.

A basic pool or spa-only plumbing diagram is helpful to pool owners with no notion of the pool. It helps them understand how a filtration setup works and pick the correct placement for pool equipment. It’s useful when building an overflow pool as it allows you to save on costs by shopping directly from swimming pool equipment dealers.

Hydraulic Plan

The hydraulic plan shows the equipment and pipes in the pump room that facilitates water filtration and treatment to ensure a safe swimming experience. Depending on the desired flow rate, PVC pipes with a 1.5′ or 2″ diameter are preferable for a private pool.

A hydraulic circuit comprises two interconnected plans:

  • Layout plan: It shows the layout of the sealed parts of the pool – bottom drains, inlets, lights, and brush socket.
  • Technical room plan: It provides the exact pool measurements – length, width, and height. The pool plumber installing the filtration apparatus must follow this plan to the letter.

Components of Pool Plumbing

A swimming pool comprises multiple plumbing components that function seamlessly. Each piece plays a unique role in keeping the water in your shared pool clean and enjoyable as you swim. It’s tempting to prioritize the more expensive features, but all parts are necessary to keep your pool usable and operational. Be sure to carefully analyze your swimming pool pump and filter installation diagram before creating any permanent seals.


Water is the central element that keeps everything in your swimming pool – systems and equipment – in excellent working order. Keep water level well-topped up to protect the spa combination plumbing equipment. You may need to add more water in summer to compensate for the loss through evaporation. Also, you may need to drain a shared pool to keep the rising water level from covering the inlets and ruining the plumbing when it rains.

Main Drain

In-ground pools have two main drains on the deep end floor to help circulate water at the bottom of the pool. Since they’re located on the lowest point of the pool, the entire pool surface slants towards the main drain. Besides helping to drain the spa, main drains suck up all the debris that sinks to the bottom. Main drains are covered with grates to keep pool users from being trapped at the bottom of the pool, as stepping on an uncovered drain can be lethal.


Also known as return jets, return are rectangular openings in the pool walls that allow the filtered pool water to flow back into circulation. Besides allowing the clean water to reenter the basic pool, the return jets also push the water around the pool. Proper water circulation in a pool is necessary to direct water into the skimmers where any floating debris is trapped in the skimmer basket.

Return Lines

Return lines are installed to carry the filtered pool water from the pump back into the basic pool through the wall return inlets.


Inground spas use one of three filters – sand, cartridge, or diatomaceous earth (DE) to clean the pool water. The filters have different pricing points and operation models, but the basic principle remains the same.

The pump forces water through the filter to trap dirt and debris, and the clean water flows back into the pipe through an outlet at the back of the pool. Filters clean the water coming from the pump by removing debris such as leaves and bugs. Advanced filters remove bacteria and hair from pool water.


A pool pump is at the heart of your pool’s filtration system. A typical pool pump uses an electric motor to create a vacuum and uses negative pressure to move the water. An impeller forces water from drains through the filters and back into the basic pool through the water inlets.

Suction Lines

Suction lines are pipelines made from PVC that connect the skimmers to the pump. When the pool pump is turned on, it uses these ducts to move water from the skimmers through suction, hence the name pool suction lines.


The skimmer is a space on your pool’s inner wall that skims water from the surface. The skimmer contains a basket that collects floating debris – twigs, bugs, suntan oil, hair, and leaves from the pool’s surface.

Sometimes a skimmer will have a weir or a floating weir, a door that’s pushed in and out by water pressure. The strainer basket catches large debris such as leaves and twigs as they flow through it. It’s crucial to consider prevailing winds when installing a skimmer in a swimming pool. The winds help move the water towards the skimmer to aid debris collection. A shared pool should have at least three skimmers, while a private spa needs two.

Optional Plumbing Equipment

If you have the budget, you can purchase optional equipment such as pool heaters and chemical feeders to improve your swimming pool experience.

Heating Components

While part of the pool’s plumbing system, a basic pool heater doesn’t interfere with the filtration or circulation system. A spa heater adds to your swimming comfort while increasing your pool season.

A pool heater is a must-have feature if you’re not a fan of swimming in cold water or have a health condition that could benefit from water therapy.

Since they come in all shapes and sizes to fit various pricing points, you’re spoiled for choice when installing a spa heater. Basic pool heaters run on propane, natural gas, or electricity, but some are solar-powered. A DIY solar-powered heater is the most affordable of the bunch since you can right it up with just a hosepipe and a few supplies. But you can also purchase a fully functional spa heater for your spa combination.

Water Treatment

A basic pool chemical feeder lets you automate one of the trickiest parts of owning a swimming pool – sanitization. These handy installations take over the sanitization process to allow proper flow of bromine and chlorine in the pool without the risk of over or under-sanitizing it.

These handy installations hook to the filtration line and have them take over the sanitization duty. Fill the feeder with the appropriate sanitizer and leave it to do the heavy lifting. You have a choice of three chemical feeders – bromine, chlorine, or mineral cartridge.

With a heated pool, the chemical feeder should be the last item on the filtration system. The chemicals may damage the heater and shorten its lifespan if you connect a feeder before the pool heater.

Pool Plumbing Diagram FAQ

If you’re new to the pool owning scene, you might have a few questions when looking at the plumbing pool diagram. This FAQ helps to answer some of the most common questions.

What Are the Two Drains at the Bottom of My Pool?

There are two main drains at the bottom of the pool to prevent main drain entrapment. Sometimes the suction at the pool with a single drain is so great that swimmers can get stuck in or on the drain. It’s part of the VGB ACT of 2007 mandated changes to prevent swimming pool fatalities.

How Do You Install PVC Pipe for a Pool?

Here’s how to install PVC pipe for a pool:
– Measure and cut the PVC with a hack saw.
– Ensure that the ends are square and clean cut.
– Bever the ends to remove burrs inside and outside the pipe to create a solid joint.
– Cover the entire length of the joint with a primer on both socket and pool pipes. An ideal pool pipe joint is about 1.5″ long.
– Apply glue on the pipe and the sockets.
– Fit the pipe and socket together, rotate them for a quarter a turn and hold them together for 30 seconds.

Do I Need a Check Valve in My Pool Plumbing?

Your pool plumbing needs a check value if you have fountains, a solar heater, a raised spa, or a raised pool pump. You’ll also need a check valve if you have a pool chlorinator, a spa blower, Ozonator, or spa overflow lines in your pool. This pool valve keeps the water flowing in one direction and stops the backflow when the pump is turned off. Jandy valves are professional-grade check valves.


Each swimming pool uses a complex plumbing system to filter and circulate the water to keep it clean and usable. It comprises eight main components located in different parts of the pool. Understanding where each element is located in a swimming pool plumbing diagram is helpful. Pool diagrams are critical when installing a pool and for routine maintenance.