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What is a swimming pool plumbing diagram ?

By April 7,2020 September 25th, 2023 No Comments

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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, such it doesn’t mention exact pipes’ layout, etc. 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.

The hydraulic circuit

It is all the pipes and equipment in the pump room that allows the pool water to be filtered and treated for a healthy swimming experience. This pipework is, for private pools, generally made of PVC with a diameter depending on the pump flow rate.

In the pool

The skimmers, the inlets, the bottom drain, and the vacuum are called fittings parts.

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 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.

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.

In the pump room

The 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.

The 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 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.

The panel control

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.

Optional equipment

The heating

This is an option. 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.

Water treatment

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 technical room, such as the salt chlorinator, ozonator, UV disinfection, etc. with the pump for pH correction.

Which pool connection diagram should I choose?

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.


Hydraulic schematic pool

The 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.

What is the purpose of this 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 overflowing 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.

swimming pool plumbing diagram

As for the schematic diagram mentioned above, the filtration is positioned hastily; a plumber will then have no difficulty in placing the equipment in the technical room.

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.

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 taken into consideration. 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!

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.

Why not take a look at our hydraulic plans?

How we design our drawings