Pool shell equipment - Skimmers, Inlets, Main drain and Overflow grating

Constructing a swimming pool can be an exciting project, but it requires careful planning and attention to detail to ensure that the pool is not only aesthetically pleasing but also safe and functional. One important aspect of building a swimming pool is the type of shell equipment that is needed to create the pool's structure.

The shell of a swimming pool is essentially the frame or foundation upon which the pool is built. The type of shell equipment required will depend on several factors, including the size and shape of the pool, the type of material used for the pool's walls and floor, and the intended use of the pool.

Some common types of shell types used in swimming pool construction include steel, concrete, and fiberglass.

  • Steel shells are often used for above-ground swimming pools because they are lightweight, easy to install, and relatively inexpensive. However, steel is not as durable as concrete or fiberglass and may rust over time, which can compromise the structural integrity of the pool.
  • Concrete shells are the most popular choice for in-ground swimming pools because they are strong, durable, and can be customized to any shape or size. Concrete pools can also be finished with a variety of materials, such as tiles, pebbles, or plaster, to create a unique and stylish look. However, concrete pools are also the most expensive and time-consuming to build, and may require periodic maintenance to prevent cracking or other damage.
  • Fiberglass shells are a newer option in swimming pool construction and are becoming increasingly popular due to their durability and low maintenance requirements. Fiberglass pools are pre-molded in a factory and can be quickly installed on site, which can save time and money compared to concrete pools. They also have a smooth surface that resists algae growth and requires less cleaning and maintenance than other types of pools. However, fiberglass pools are not as customizable as concrete pools and may not be suitable for all types of soil or climate conditions.
Pool Shell made of concrete Pool shell made of liner

What equipment is needed for concrete swimming pools

Concrete swimming pools are a popular choice for many homeowners due to their durability and versatility. When it comes to choosing the right shell equipment for concrete swimming pools, there are a few factors to consider. First, you will need to decide on the type of finish you want for your pool. Concrete pools can be finished with mosaic, tile, or other types of decorative finishes.

If you decide to go with mosaic or tile finishes, you will need to choose a shell equipment that is compatible with those finishes. Some popular options include pool skimmers, returns, and main drains. Additionally, you may want to consider installing an automatic pool cleaner to help keep your pool clean and free of debris.

What equipment is needed for liner swimming pools

Liner swimming pools are another popular choice for homeowners. These pools are constructed with a flexible PVC membrane that is stretched over a frame and secured to the pool's walls and floor. Choosing the right shell equipment for liner swimming pools is important to ensure that your pool operates efficiently and effectively.

When it comes to choosing shell equipment for liner pools, you will want to look for equipment that is designed specifically for use with PVC membrane liners. This includes pool skimmers, returns, and main drains that are compatible with liner materials. Additionally, you may want to consider installing a pool liner vacuum to help keep your liner clean and free of debris.

However, choosing the right equipment for your swimming pool can be overwhelming, especially if you are new to the world of pool ownership.

What type of shell equipment is needed while constructing a swimming pool.

Swimming pools are a great way to cool off, exercise, and relax during the hot summer months. However, keeping a pool clean can be a daunting task, and that's where few shell equipment like skimmers, inlets, main drain, overflow grating, comes in handy

What are skimmers?

Skimmers are an essential part of a swimming pool's circulation system, and they play a crucial role in keeping the water clean and free of debris.

A pool skimmer is a device installed in the side of a swimming pool, typically near the top, that helps remove debris from the water's surface. Skimmers are usually made of plastic or metal and have a basket or trap that collects leaves, insects, and other floating debris. The skimmer then sends the debris through the pool's filtration system to remove contaminants and return clean water to the pool.

Wall mounted Skimmer Wall mounted Skimmer

How do skimmers work?

Skimmers use the pool's circulation system to draw water through the skimmer's opening and into the collection basket. As water enters the skimmer, it creates a flow that pulls debris towards the opening. Once the debris is caught in the basket, the water continues to flow into the pool's filtration system.

Why are skimmers important?

Skimmers play a crucial role in keeping a pool clean and healthy. By removing debris from the water's surface, skimmers prevent it from sinking to the bottom of the pool, where it can clog the filter system and create a breeding ground for bacteria and other harmful organisms. Skimmers also help maintain the pool's water level by removing excess water, preventing damage to the pool's structure and surrounding landscaping.

Skimmers come in various sizes like wide or standard, and different materials like ABS or stainless steel. They are also designed based on different flow rates.

In addition to their functional benefits, skimmers can also enhance the aesthetic appeal of a pool. They are available in a variety of colours and styles, so homeowners can choose a skimmer that matches their pool's design.

How many skimmers are required according to the pool volume?  

The number of skimmers required for a pool depends on the size of the pool and the flow rate of the water. In general, a skimmer should be able to process the entire volume of the pool at least once every 4 hours.

To calculate how many skimmers are required for your pool, you will need to determine the volume of your pool and the flow rate of your pump. Once you have this information, you can select the appropriate skimmer(s) for your pool.

For example, let's say you have a 50 m3 pool with a standard flow rate of 12.5 m3 per hour. In this case, you will need one skimmer with a flow rate of at least 12.5 m3 per hour.

A wide skimmer typically has a flow rate of around 12 m3 per hour, which would be sufficient for this pool. Alternatively, you could use two standard skimmers, each with a flow rate of around 5-6 m3 per hour, to achieve the necessary flow rate.

What are inlets?

Inlets are a crucial component of a swimming pool that are responsible for introducing clean and filtered water into the pool. They are typically located on the walls of the pool and are strategically positioned to ensure maximum water circulation.

Inlets are used in swimming pools for a variety of reasons. Firstly, they help to maintain the pool's water level by introducing water into the pool as it evaporates or is lost through splashing. This ensures that the pool is always at the optimal water level, which is important for both safety and comfort.

Return inlet in pool Water inlet in swimming pool

How do inlets work?

Inlets also play a vital role in keeping the pool water clean and clear. As water is introduced into the pool through the inlets, it is forced to circulate throughout the entire pool, which helps to distribute chemicals such as chlorine or salt, as well as any other treatment products, such as algaecides or clarifiers. This circulation ensures that the water is properly treated, which helps to prevent the growth of bacteria and algae, as well as other harmful contaminants.

Types of inlets commonly used in swimming pools

Return Inlet: This type of inlet is used to return filtered water back into the pool. It is typically located near the surface of the water and creates a gentle flow that helps circulate the water and distribute chemicals. Vacuum Inlet: This type of inlet is used to connect a pool vacuum to the pool's filtration system. It is typically located on the pool floor and allows the vacuum to remove debris from the bottom of the pool. Suction Inlet: This type of inlet is used to draw water from the pool into the filtration system or to water attractions. It is typically located near the bottom of the pool and creates a strong suction that helps to remove debris and maintain water clarity.

Note: The inlet can be wall mounted or bottom mounted and for liner or concrete pool.

How many Return inlets do you need for a pool

The number of return inlets required according to a skimmer quantity depends on the size and type of the skimmer.

For wide skimmers, it is recommended to have 3-4 return inlets for each skimmer. This is because wide skimmers are designed to handle a larger volume of water and require more flow to properly function. With more return inlets, the water can be distributed more evenly throughout the pool, ensuring that all areas are properly filtered.

For standard skimmers, it is recommended to have 2 return inlets for each skimmer. Standard skimmers are designed for smaller pools and require less flow than wide skimmers. With two return inlets, the water can be evenly distributed throughout the pool while still providing sufficient flow for the skimmer to properly function.

It's important to note that the number of skimmers and Return inlets required may also depend on the shape and design of your pool, as well as other factors such as wind and water currents. It's always a good idea to consult with a professional pool technician to ensure that your pool is properly equipped with the appropriate skimmers and other equipment.

What is a Main Drain in a Swimming Pool?

One of the most critical components of a swimming pool is the main drain

A main drain is an essential part of a swimming pool's circulation system. It is usually located at the deepest point of the pool and is designed to remove water from the pool. The main drain is connected to the pool's circulation system, which includes the pool pump and filter, to ensure that the water is filtered and sanitized before returning to the pool.

A single main drain is sufficient for a pool with a capacity of up to 100 m3.

Main drain for pool Main drain for pool

Functions of a Main Drain in a Swimming Pool

Water Circulation: The main drain plays a crucial role in the pool's water circulation system. It helps to pull water from the pool and sends it to the filter and pump for cleaning and sanitizing. This process ensures that the water is always clean and safe for swimmers. Debris Removal: The main drain also helps to remove debris such as leaves, insects, and other contaminants from the pool. This is especially important in outdoor pools where debris can accumulate quickly. Equalizing Water Pressure: The main drain helps to equalize the water pressure in the pool, which can prevent damage to the pool's walls and floor. Uneven pressure can cause tiles to crack and even cause the pool to shift or move. Preventing Pool Drain Suction: The main drain is also designed to prevent pool drain suction, which can be dangerous to swimmers. Suction from a pool drain can cause a swimmer to become trapped, leading to drowning or injury.

Overflow grating

An overflow grating is typically installed along the edges of the pool, where it functions as an inlet for water to enter the pool while simultaneously removing any excess water that overflows from the sides.

The size of the swimming pool determines the necessary dimensions of the overflow grating.


Overflow grating for pool Overflow grating for pool

How an overflow grating works

  • Ensure that the pool water remains at a consistent level, regardless of the amount of water entering or leaving the pool. This is especially important in large public swimming pools or Olympic-sized pools, where there may be a significant amount of water entering and exiting the pool at any given time.
  • Maintaining the cleanliness of the pool. By removing excess water from the sides, it prevents debris such as leaves, insects, and other unwanted material from entering the pool. This not only makes the pool more visually appealing but also helps to prevent potential health hazards caused by contaminated water.
  • Improve the safety of the pool. By preventing water from overflowing onto the pool deck, it reduces the risk of slip-and-fall accidents and helps to maintain a safe and dry environment around the pool.

Design: Overflow grating is typically made from durable materials such as PVC or stainless steel, which are resistant to the corrosive effects of pool chemicals and exposure to sunlight. They are designed to be easy to install and maintain, and many come with built-in features such as snap-on covers or removable screens that make cleaning and maintenance a breeze.