The technique of the infinity pool
Overflow is primarily a hydraulic principle and it is useful to specify its main characteristics:
- Most overflow pools are built in concrete, although a few manufacturers of pool kits or shells have entered this market.
- An overflow pool is either in-ground or partially in-ground
- The filtration system installed in the technical room is very similar to that of a skimmer pool. The additional equipment is detailed below.
- All linings can be used: liner, reinforced PVC, polyester, tiles, …
The quick schematic diagram below will help you to find your way around easily, without having to use too complicated words.
In the regular swimming pool, the water is sucked in by the pump through openings called skimmers; it is then filtered and pumped directly into the pool; it is a closed circuit. The only loss of water, apart from the washing of the filter, is due to evaporation in the pool, mainly in summer. The water level is about 15 cm below the coping stones.
In the negative edge pool or the zero-edge pool, the water is not sucked into the pool but into a so-called “balancing” tank; after filtration, the water is returned to the pool through outlets (generally in the walls and at the bottom) and can only overflow since the pool is already full! The water flows into a gutter where it is collected and then redirected by gravity into the balancing tank.
As for the skimmers, we are in the presence of a closed-circuit: it is the same water that circulates, so there is no special anxiety about water consumption. Here the water line is 3 to 4 cm under the coping or even at the same level if it’s a zero-edge pool.
They are essential to an infinity pool construction and are not necessarily expensive.
The balance tank also called a surge tank or catch basin is, of course, essential for the operation, since it is from there that the water will be sucked by the pump to make the pool overflow. To determine the surge tank capacity, we consider the volume of the pool but also the pump flow rate, the length of the overflow, and the expected number of bathers. Too small will be insufficient in case of rainwater or overuse of the pool, and you will waste water; too large is money wasted on masonry and chemicals.
The function of the gutter is to collect the water that overflows from the pool and fill the tank. Its location depends on the overflow type; it is placed below the side(s) through which the water spills on a waterfall pool. A zero deck level pool has a channel located around its entire perimeter. The bottom inlets (not to be confused with the bottom drain) are often forgotten, but they are essential in reverse hydraulic.
The water level controller in the catch basin is also crucial. Its function is to make your life easier and avoid important water losses or big problems at the pump. More or less economical solutions exist floats, probes, bubblers. The check valve and a solenoid valve to fill the tank automatically are also necessary. See our post about balancing tank level control.
Let’s explain what is true and what the rumor is about the technique of the infinity pool.
The balancing tank must be at least 10% of the pool volume: this is FALSE. It is much less. The volume of the pool but also the filtration pump flow rate, the length, and the kind of overflow are used to calculate the balance tank capacity.
A second pump is necessary: this is FALSE. If the masonry has been properly done, this pump is useless. However, this is only true for a small pool with a long overflow length, for instance, a mirror pool, or when you want to increase the water level of the overflow to hide a defect in the level of the overflow.
The filtration must be oversized: this is FALSE for the same reasons as above.
A special disinfection system is mandatory. NO! We advise our customers to equip their pool with an automated treatment, but you can also add chlorine manually. The proof: infinity pools existed long before salt disinfection or other automatic systems were available on the market!
It is impossible to install an immersed cover on an overflow pool: this is FALSE. Otherwise, nobody would want to build one anymore. Many suppliers are on the market, but many of our customers have been satisfied with AZENKO.
It is impossible to transform a skimmer pool into an overflow pool: This is FALSE. You will find an example in this post.
The price of an infinity pool is higher than that of a skimmer pool: it is TRUE! You have to count between 20 and 25% more. But by building it yourself or with non-specialized craftsmen, you can save up to 30%. I’ll let you do the calculation. We will help you in this process.
The advantages of an infinity pool
They are of two kinds: technical and aesthetic
The main technical advantage is cleaner water. Indeed, the water is perfectly recyclable over its entire surface where the pollution is the strongest: surrounding dust, solar oil, pollens, …! The bottom inlets allow impurities to rise to the surface. It results in fewer dead water zones and better efficiency of the treatment products. It is not for nothing that public swimming pools have been overflowing for a long time!
Just look at the pictures of overflowing pools to understand the visual effect and aesthetic interest. A negative edge pool built on a sloping plot opens up the horizon, but you don’t need a panoramic view! A zero-edge pool with the water level at the same level as the coping stones brings a calm atmosphere to a garden, even if it is small.
Studies prove that a swimming pool adds between 5 and 20% to the value of a house. It goes without saying that an infinity pool will bring even more.
How to reduce the cost of an infinity pool?
Although an infinity pool is technical, it can be built by companies that do not specialize in swimming pools. This way you can make your dream come true without breaking the bank.
We can help you in your infinity pool construction in these ways:
- We will create a unique design for you that matches your property and your wishes.
- Furthermore, we design precise general plans and hydraulic layouts so that masonry and plumbing companies can carry out the work.
- Not only that, but we help you by following remotely the construction site from the start of your pool until commissioning.
Perhaps would you like to know more about us before contacting us !