There are many articles about the aesthetics of infinity pools, like the water line that merges with the horizon or the mirror effect of the pool surface. There’s more. The water quality is also better.

An Overview Of The Vanishing Edge Overflow Technique

Essentially, overflow refers to a reverse hydraulic system that maintains clean water and stirs maintenance products effectively.

Special features of the construction

Essentially, overflow refers to a reverse hydraulic system that maintains clean water and stirs maintenance products effectively.

  • Most pools are reinforced concrete (poured or shotcrete) in free-form or rectangular shapes. Steel or wood can be used as forms. As lost formwork, concrete, or polystyrene shuttering blocks can also be used. Kit pools and shells are now available from some manufacturers.
  • Overflow pools are typically in-ground (buried or semi-buried) depending on the land’s profile.
  • The filtration system installed in the plant room is very similar to that of a regular pool. In the following paragraphs, we list additional equipment.
  • Various pool surfacing materials can be used: reinforced PVC membranes, polyester resin reinforced with fiberglass, mosaics, waterproofing and finishing coatings. Even in a small masonry pool, a regular pool liner is not ideal.

Filtration system features

piscine débordement technique

A quick diagram is provided here to illustrate the difference between a skimmer pool and an overflow pool.

Regular swimming pools have skimmers in the walls that collect water from the pool; the water is filtered and returned directly to the pool through the return inlets, creating a closed circuit. Water level is about 15 cm below coping stone level.


Water is not drawn directly from the in-ground pool in the infinity pool or the peripheral overflow pool. Gravity reroutes overflowing water into the surge tank or balancing tank by collecting it in a channel or gutter. After filtration, the water is returned to the pool through inlets located on its wall and bottom.

As with traditional pools, it is the same water that circulates in the pool. Therefore, contrary to what is written on the internet, there is no overconsumption of water.

The water level in these vanishing edge pools is close to the coping stone. Whenever there is a mirror effect in a deck level pool, the water level and the deck level are the same.

Morana's advice 👇

A tailor made infinity swimming pool

Architects and pool builders can design and build this type of pool, but if you want more control and want to save money, you’re probably better off working with a pool designer and construction company.

Affordably build a pool

Despite infinity pools being technically complex, non-specialized companies can build your dream pool at a reasonable price.


Seek professional support for your pool project.

Technical benefits of an overflow pool

The installation of a vanishing edge pool allows bathers to enjoy a more comfortable bathing experience. With the flow of water from the bottom to the top, treatment products and heat pump-heated water are better mixed. This means that maintenance of the pool and the treatment of the water are made easier. Salt chlorinators replace chlorine for swimmers’ pleasure. Previously reserved for public pools, private pools can now use the overflow system. Once reserved for public pools, the efficiency of overflow is now available for private pools.

And the aesthetic advantages

Take a look at a picture of an overspilling pool to understand the visual effect. Infinity pools built on slopes have a water line that blends with the skyline. The zero-edge pool transforms a garden into a relaxing space where the water level matches the deck or terrace. Instead of a grate, water flows through a discreet slot.

The Icing on the cake is that a swimming pool adds between 5 and 20% to a house’s value. Even more if there’s an overflow pool.

An Overview Of The Equipment Required

When building a semi-inground or inground pool that spills over, it is imperative to integrate overflowing pool equipment. These items are not costly to purchase, but they are crucial to ensuring the longevity of any indoor or outdoor swimming pool. If you do not buy them, using and maintaining the pool can be quite a hassle.

Without a catch basin or surge tank, the pool cannot spill over. Excess water stored in this small basin is sucked in by the filtration pump, allowing the pool to overflow. Several articles have been written about the calculation of its volume; it is necessary to take into consideration not only the volume of water in the pool, but also the length of the overflow and the number of expected bathers. Water will be lost through the overflow if the sump is too small to handle rainwater or excessive numbers of swimmers. It will waste money during construction if it is too large.

An overflow channel serves to collect water spilled over from the main pool and feed the catch basin. The location of this device depends on the type of overflow; in the case of an infinity pool, it is located beneath the side(s) from which the water overflows. The deck level pool will have it all around.

Inlets integrated into the bottom of a luxury pool (not to be confused with the bottom drain) are often overlooked but are essential for reverse flow.

It is also essential to have a water level regulator in the balance tank. Therefore, it simplifies your life and helps you avoid damaging consequences, such as a lack of water. There are several more or less economical solutions available: floats, probes. A non-return valve and an automatic filling solenoid valve are also necessary.

For more information about balance tank regulations, please refer to our post.

Let’s Look At The Truth About Overflow Pools

There are many misconceptions about infinity pools circulating on the Internet. They’re often the same, and for the most part unfounded.

Infinity pool design

The balancing tank must represent at least 10% of the pool’s volume. It is much less than that. Besides the dimensions of the pool, the calculation considers the flow rate of the pool filtration pump as well as the length of the overflow.

It is widely believed that a second pump is required. NO! The second pump is often used to increase the thickness of the water layer to compensate for a poorly executed overflow (non-horizontal level). In the case of a small pool with a long overflow, however, this may be true.

The filtration system for a swimming pool must be oversized: this is FALSE. The same reasons as above apply.

Infinity pool options

A submerged cover cannot be installed on an overflow pool: this is clearly INCORRECT. Otherwise, no one would be interested in building one. Most pool covers and enclosures can also be installed. A movable floor is a more expensive but very interesting option.

Pool maintenance

Overflow pools require more maintenance:NO! In fact, the opposite is true. As the water flows from the bottom of the pool to the surface, dirt does not settle and algae does not grow in an infinity pool. Impurities are transported to the gutter by the flow of water through the overflow.

Lowering The Price Of An Infinity Pool

If you’re proud owner of a regular pool with skimmers It is impossible to convert a pool with skimmers into a vanishing edge  pool. An in-ground concrete pool can be renovated using the existing framework. There is the possibility of adding some features, such as an underwater deck, stairs, or a relaxation area.

Building an infinity pool is more expensive than building a pool with skimmers! Ten to fifteen percent more should be added. Nevertheless, you can save up to 30% by building it yourself or hiring a non-professional pool installer. Whatever your pool needs are, we can help you to create them, whether they are modern pools or swimming corridors for example.  Find out more about our services and ask us for a quote.