How does a swimming pool filtration system work?
Keen to have the complete pool filtration system and its importance for both hygiene and safety purposes explained by an industry expert? You’ve come to the right place!
At the Chemsol Group, our team of fully qualified pool engineers have designed, installed, and maintained countless swimming pool filtration systems for both residential and commercial customers across the UK.
If you want to ensure the water in your pool or spa is always clean and sanitised for your family or customers, then picking the most suitable swimming pool filtration system is essential. Here’s where we can help.
Simply carry on reading to find out how a swimming pool filtration system works and the significant role it plays in clarifying the water, preventing the spread of germs and bacteria, and combatting algae growth.
What are the components of a swimming pool filter system?
More than just filtration equipment, a complete swimming pool filter system consists of a variety of essential components, including:
- Pool main drain and skimmers
To suck in dirty water that might be contaminated by leaves, skin, or hair, swimming pools feature a main drain at the bottom of the pool and a series of openings that are built into the walls.
These openings are known as pool skimmers and they’re just as crucial as the main drain to starting off the pool water filtration process.
- Pumps
While the main drain and skimmers are openings for water to be pulled through, it’s the pool filter pump that’s creating this suction and circulation. The pump creates continuous motion which circulates the water through the filter, thereby preventing stagnation and stopping dirt and debris from accumulating.
There are three main types of pool filter pump: single-speed, two-speed and variable-speed pumps. While both single and two-speed pumps are powered by induction motors, they differ in that only double-speed pumps have both a low-speed and a high-speed option.
This makes double speed pumps more efficient than the single alternative as it won’t be running on high speed all the time. Variable speed pumps, on the other hand, are fitted with a permanent magnet motor and are far more energy-efficient than both single and double-speed pumps.
- Pool filters
After the pool pump, the water is pushed onto the swimming pool filter. As the name suggests, this key part of the system is designed to clarify the pool water by filtering out debris and other unwanted particles using a porous material
Essential for sanitation and enjoyment purposes, there are three main types of pool filtration system material - sand, DE (diatomaceous earth), and cartridge. Each type of pool filtration system differs in cost and maintenance, so it’s important to weigh up their individual advantages and areas to consider.
However, while they all work slightly differently, their common aim is to remove dirt, debris, and bacteria to help prevent unwanted issues such as the spread of infection and growth of algae.
- Heaters
Before the clean and sanitised water can be returned to the pool, it’s typically fed through a heater to be warmed up. While there’s a variety of pool heating systems, including gas, electric resistance, solar, and heat pump, they all do the same job of ensuring the water is kept at the perfect temperature no matter the season.
- Plumbing and valves
Throughout the water flow pathways of the swimming pool pump and filter system there’s also various valves installed in the plumbing. Despite their small size, these valves ensure that the water is travelling in the right direction, while simultaneously preventing dirt and debris from flowing back into the swimming pool.
On top of being used to carefully control the water flow, these valves are also crucial for adjusting the water pressure and stopping water from entering areas of the pool system that are undergoing routine maintenance or being repaired.
How the swimming pool filtration system works
The pool filter system filtration process varies slightly depending on the material used to purify the water, but regardless of which type of swimming pool filtration system you use, the basic process will remain the same.
There are three key stages to any pool filtration process – water circulation, filtration, and the returning of clean water to the pool. We explain each stage in more detail below.
Water circulation
As touched on above, the pump, main drain and skimmers all work together to help promote constant pool circulation. This circulation is not only essential for pushing dirty water towards the pool filter, but it also plays a crucial role in ensuring all the pool chemicals are evenly dispersed.
Good water circulation also contributes towards the maintenance of a consistent pool water temperature, delivering a better user experience. The final benefit of water circulation is that it prevents areas of the pool from sitting stagnant as stagnant water breeds bacteria and debris.
Filtration mechanism
Searching for the most suitable filter for your swimming pool? There are three main types of filtration mechanisms commonly used: Sand, DE (Diatomaceous Earth), and Cartridge systems. Here's how each works:
- Sand Pool Filtration System Process
To filter out dirt and debris between 20-40 microns, sand pool filtration systems use slotted lateral pipes to evenly disperse water across a chamber filled with sand. The sand allows water to move through, while retaining any impurities.
- Diatomaceous Earth (DE) Pool Filtration System Process
DE pool filtration systems use sponge-like organisms in diatomaceous earth powder to filter out impurities between 3-5 microns. This powder is used to coat a selection of grids that the pool water is passed through, catching dirt and debris in the process.
- Cartridge Pool Filtration System Process
With the ability to remove impurities as small as 10-15 microns, cartridge pool filtration systems use a layer of synthetic fabric (a cloth-type material) folded into pleats. Pool water is simply pumped through this fabric layer to filter out dirt and debris.
- Glass Media Pool Filtration System Process
Glass media filters use specially designed glass beads or crushed recycled glass as the filtration medium. These filters are highly effective in removing particles as small as 5-10 microns. The smooth surface of glass media prevents clogging and requires less backwashing compared to sand filters. It's a more environmentally friendly option as well, using recycled glass and offering improved performance over traditional sand.
Returning clean water
Once the water has gone through the pool filter system and has been heated to the preferred temperature, it’s returned to the pool via the return lines and jets. The water should be clear, warm, and free of contaminants, ensuring a safe and pleasant swimming experience.
Maintenance of pool filter systems
Proper maintenance is essential to keep your pool filtration system functioning efficiently and ensuring the longevity of your equipment. Regular cleaning and monitoring of water quality are necessary, but the maintenance requirements vary depending on the type of filter you have. Here's how to care for each system:
Sand or DE pool filtration system
Backwashing is vital to maintain your sand pool filter or DE pool filter in good condition. This process involves reversing the flow of water into the pool’s filter which essentially flushes any trapped contaminants or debris from the sand or diatomaceous earth.
This unwanted debris is then expelled directly it into the pool’s drain or waste line. As a result, backwashing helps to support the efficient performance of your sand or DE filter. Backwashing is generally recommended every 2-3 weeks to ensure a clean and effective filter.
Cartridge pool filtration system
Most cartridge pool filters will need to be manually removed and cleaned to maintain their effective filtering qualities. The most common cleaning procedure for a cartridge filter is to simply rinse the filter using a garden hose. Simply work from the top down to push debris out and way from the pleats.
If the filter becomes damaged (e.g., cracked or ripped), it will need to be replaced, as it can no longer filter effectively. However, a change in colour of the cartridge is normal and does not necessarily mean it needs to be replaced.
Water Quality Monitoring
Regardless of the type of pool filter, however, you should also be regularly monitoring the water quality. This is because both heavy rainwater and water temperature can impact the chemical balance, which in turn can lead to a higher risk of corrosion to the swimming pool filtration system.
Maintaining the proper chemical balance (of both chlorine and pH) is therefore vital if you want to extend the life of your equipment and prevent further damage. Typically, you should be testing your pool water's chlorine and pH levels every two weeks.
PWTAG Standards
To ensure the highest level of quality and safety, it is advisable to invest in filtration equipment that meets PWTAG (Pool Water Treatment Advisory Group) standards. These guidelines are based on the best industry practices and are endorsed by the Health and Safety Executive (HSE) and local authorities in the UK. Following these standards will help ensure the effective management, maintenance, and safety of your pool.
Contact Chemsol Group for Professional Pool Filtration
At Chemsol Group, our team of qualified pool engineers understands the significant impact a well-functioning filtration system and regular maintenance have on water quality and user experience.
We offer consultancy and site visits to assess the best filtration solutions for your pool, ensuring compliance with the latest PWTAG guidelines. We also provide a range of custom pool filtration packages for both commercial and residential environments, tailored to meet your specific needs with varying levels of support, automation, and features.
For more information on our pool filtration packages or the filtration process, call us at 01492 582 888, email info@chemsol.co.uk, or complete our online contact form. We look forward to helping you with your pool plant room requirements!