The swimming pool plumbing diagram shows how to connect the various components of the swimming pool filtration system: swimming pool pump, filter, water disinfection, heating, etc. It shows schematically all the equipment selected and the way they are connected. The goal of a filtration diagram is only to understand the filtration concept; for that reason, it doesn’t mention exact pipes’ layout, fittings, or other accessories, as they will be designed precisely in the installation layout drawing.
The Swimming Pool Filtration System
We detail here the different equipment that make up what is called a pool filtration system. It includes pool stuff as well as that in the plant room.
The Hydraulic Circuit
Hydraulic networks are the pipes that allow water to circulate between a swimming pool and its equipment room. In private pools, this piping is generally made of PVC, with a diameter that varies according to the pump’s flow rate. Proper plumbing plays a crucial role in the pool design process, as it determines the efficient flow of water throughout the pool system. Proper pipe routing ensures that water is distributed evenly to all areas of the pool, including the filtration components, ensuring optimal circulation and filtration for clean and clear water.
For pools with spa combinations, it’s essential to consider the plumbing layout carefully. Jandy valves are beneficial for controlling the flow between the pool and spa, making it easy to manage different water circuits. These valves revolutionize pool plumbing by allowing control over two pipes with one valve, increasing efficiency and ease of use. Additionally, implementing check valves ensures that water does not backflow, which protects your equipment from damage. Be sure to include anti-siphon valves in your design to prevent any unintended drainage.
The pool shell equipment
- The skimmers
Through this rectangular mouth, the dirty surface water is sucked in by the pump and fed into the filter circuit. They are installed under the coping stones, on the wall facing the prevailing winds, and the water level must always be kept in the middle of the opening. There is one skimmer per 269 sq ft (ca. 25 m²) of water surface.
Note: in overflow pools, the skimmers are removed and replaced by a gutter connected to a balancing tank. See the article on the principle of overflow.
- The return inlets
The return of clean water to the pool is done through these holes. They are usually positioned on the wall opposite the skimmer wall. In addition, there are bottom inlets for the overflow pools.
- The bottom drain
Installed at the bottom of the pool, it sucks up, like the skimmers, the dirty water from the bottom of the pool and sends it to the filtration unit. It is not mandatory, but also allows the pool to be drained if necessary and to better stir the water. Especially in pools without water level regulators, it is advisable to maintain a slight suction through the bottom drain to avoid “burning” the pump in case of a drop of the water level in the skimmers.
- The vacuum inlet
It is used to connect a hand-held vacuum cleaner to clean the pool walls and floors.
- The LED lighting
It is not part of the hydraulic circuit, but is considered to be an aspect of the pool shell equipment.
The pump room equipment
The pump room serves as the heart of the pool’s filtration and water treatment systems. This area houses the pumps, filters, and chemical feeders necessary for maintaining clean, safe water. Accurate layout plans and plumbing diagrams ensure that all components fit perfectly and operate in harmony.
- Pump
It is the heart of the system; together with the filter, it forms the filtration unit. It sucks the dirty water out of the pool and returns it to the filter. Furthermore, it must be calibrated according to the volume of the pool. Any pressure losses due to the difference in height or the distance between the pool and the pump room must be considered.
- Filter
The water pushed by the pool pump flows through this tank filled with a filter medium and comes out of it free of all impurities. The most commonly used is the sand filter, but on a small pool or an above ground pool, the cartridge filter is a suitable option. For exceptional filtration fineness, the diatomaceous earth filter is a good choice. Recycled glass, as a replacement for sand, is increasingly used because it offers a better filtration fineness and does not scale so much. In commercial pool settings, high-rate sand filters are more popular due to their efficiency in handling large volumes of water.
- Valves and security features
Another significant element in pool plumbing is the check valve. This device helps prevent backflow, ensuring water flows in the correct direction, thus protecting your filtration system. Modern check valves often come with see-through lids, making it easier to inspect and maintain. Additionally, do not forget to include union fittings for easy disconnection and maintenance of pipe segments.
- Water treatment
It is optional. Several systems exist to disinfect the water after filtration. If you no longer wish to use the chlorine tablets, various automatic systems can be installed in the plant room, such as the salt chlorinator, ozonator, UV disinfection, etc.
- Pool pH regulation
It helps to maintain the pH level required for proper water disinfection.
- Pool heating
It is also optional. The swimming pool heat pump is the most widely used and most cheap in operation. Installed outdoors, it is connected to the filtration system using two hoses connected after the filter. It is recommended to install it as a bypass to isolate it in case of intervention on it. For small basins or spas, the electric heater, which allows a rapid rise in temperature, is preferable. It is installed in the pump room. Cheap to buy, it is expensive to use.
- Return lines
These PVC pipes help guide the filtered water back into the pool. Ensuring these return lines are properly installed prevents potential leaks and guarantees a steady flow of clean water back into your pool. Return lines, along with skimmers and main drains, are the key components in maintaining balanced water circulation, especially in large inground pools.
Control panel
It must be connected to a protected main supply line. It is used to supply all the electrical equipment required for the proper functioning of the pool.
Morana's advice 👇
Make sure you’re prepared
More precise diagrams or plans will help you visualize the installation and prepare all the necessary equipment. It ensures smooth and efficient installation.
Don’t underestimate filtration’s importance
The filtration system is the heart of a swimming pool, and the pipes are its veins. To ensure that a pool functions properly, not only must the filtration unit be properly sized, but the water must also flow through the pipes.
Get the right support for your pool project.
Which Pool Connection Diagram Should I Choose?
What is the purpose of a swimming pool filtration diagram?
Its first function is to clearly show the water circuit from the departure of the pool to its return, with valves and non-return valves in the right place without forgetting them.
In the case of an overflow pool, forgetting a non-return valve can lead to the accidental emptying of the pool. A forgotten valve can, among other things, make it difficult to temporarily isolate part of the filtration circuit for repair or maintenance.
The basic pool connection schematic
It corresponds to a typical pool, usually with skimmers. The equipment is not calibrated according to the volume of water in the pool. Its purpose is simply to explain the path of the water through the filtration circuit. It is interesting because it allows neophytes to understand how a pool works. It will show you where the equipment such as pump, filter, heating, disinfection are typically located. Furthermore, it is often found for a skimmer pool but more rarely for an overflow pool.
This is obviously the least precise document. It’s of no use if you want to install your pool filtration system.

The tailor made filtration diagram
What’s that? It’s the hydraulic design of YOUR pool. It will take the equipment that makes up the filtration and place them in the right place in relation to each other. Not only that, but it shows empirically the arrival and departure of the pipes between the pool and the room. Then the pump, the filter, the devices such as the disinfection device, the pH control, the heating, etc. are positioned.
It considers the volume of water in the pool and includes the exact number of pipes, spotlights, etc., necessary for the filtration to work properly. For an overflow pool, the volume of the balancing tank is also mentioned.

Hydraulic plan of the swimming pool
It’s more than just a swimming pool piping diagram. It consists of two separate but interconnected plans:
Based on the pool plan, a layout plan of the parts to be sealed (inlets, bottom drains, brush socket, lights) in the pool is made. For maximum filtration efficiency, especially in an overflow pool, their number and positioning should not be left to chance. From this point on, the hydraulic network must be built to pass under the pool’s invert before starting the actual masonry work. For example, it is necessary to balance the networks so that the same flow of water arrives at each inlet. In this same step, the lighting must be provided. If you’d like to see some samples of our plans, click here!
The plan of the plant room is drawn with the exact measurements of the space dedicated; not only the length and width but also the height are considered. The plumber who will install the filtration will only have to follow the plan to the letter. No problems with crossing pipes or equipment that does not fit in the technical room. Yes, we saw that too! Ensuring there are enough drainage points and that they are adequately covered adds to the operational ease and longevity of the system.
What’s The Point Of Having A Swimming Pool Connection Diagram?
A basic diagram will not consider the specificity of your pool and will be useful if you have no notion of the pool. Thanks to it, you will understand the basics of filtration, and you will know where to place the equipment.
The basic diagram adapted to your pool will give you a little more information. If you have some knowledge of plumbing and your pool is relatively simple, this will be enough for you.
On the other hand, if you want to build an overflow pool, and you are thinking of using a general plumber, we advise you to have a complete hydraulic plan. You will be able to buy the equipment directly from the swimming pool equipment dealers and make real savings; these savings can be estimated at USD 3,000 for an infinity pool of 33 feet (ca. 10 m) x 16 feet (ca. 5 m).
Where Can I Find A Swimming Pool Plumbing Diagram?
The simplest ones can be found on the internet, for example in generalist pool sites, which are full of ideas on the subject.
For a piping diagram adapted to your swimming pool project or even a plan, you will need to call in a professional. Plumbers can not always do this, but equipment suppliers sometimes offer to provide you with installation diagrams, which are usually provided after you buy the equipment.
Swimming pool designers also provide these documents. It is indicated on the pool general plan where pipes are routed and where the pool shell equipment is located. Each filtration component is displayed on the equipment room plan with its actual dimensions.