How to Maintain a Swimming Pool Filter

It could be argued that the filter on your swimming pool is the most important system for ensuring your pool water is crystal clear and free from contaminants. By working automatically, the pool filtration system cleans pool water by trapping debris and particulates.

Although pool filters remove most of the need for manual pool cleaning, the filter systems themselves must be maintained so they can continue to perform at expected levels. In official documentation from the World Health Organization (WHO), proper filtration is recognised as an essential factor in managing water quality in swimming pools and other recreational environments.

In this article, we discuss professional strategies for cleaning and protecting swimming pool filters. This includes a focus on the industry-leading products from Waterco, along with advice on how to choose the best filter for your type of pool. Whether you’re a pool owner or a dealer recommending clients, there will be practical maintenance tips for filters.

The Importance of Pool Filter Maintenance

Every part of the pool, from the skimmer system and covers to the water, requires some form of maintenance to ensure a comfortable and safe experience for your guests. Following the different approaches for each can get complex, but it’s also worthwhile, as proper maintenance will help avoid breakdowns and save repair costs.

Swimming pool filters perform a vital function in both residential and commercial swimming pools, being designed to trap various kinds of debris that collects in the pool water and on its surface. This could be microparticles, dirt, or large debris such as twigs and leaves.

Clogged, damaged, and neglected filters can lead to:

Murky water
Increased strain on pumps
Premature equipment failure
Higher chemical usage
Unnecessary running costs

Owners must understand how a swimming pool filter works to properly maintain the system and protect the rest of the pool. If the filtration system develops a malfunction, knowledge of each of the parts involved in its function will help you diagnose the problem and perform more targeted maintenance.

Types of Swimming Pool Filters and How They Work

Sand Filters

Water is forced through specially-graded sand, designed to trap particles as small as 20-40 microns wide. The filtered water is then returned to the pool via the outlet pipe. Maintenance for these pool filters should include backwashing to ensure the sand gets cleaned. Further maintenance checks should be done on the filter shell, which can be made from metal, concrete, or fibreglass.

Catridge Filters

Water is funnelled through pleated polyester cartridges, which trap small debris, down to 10-15 microns. These cartridges need to be removed and rinsed to maintain filtration. Although eventually they will need to be replaced altogether.

Diatomaceous Earth (DE) Filters

DE powder coats the inside of these filters, capturing particles as small as 3-5 microns. There can be many elements within the filter coated with DE, all of which must have it reapplied during the filter’s lifespan to maintain effectiveness. Backwashing is also necessary to clean these elements at regular intervals.

Expert Pool Filter Maintenance Tips

1. Regular Cleaning and Machinery Servicing

Routine cleaning and servicing are essential to maximise the lifespan of filtration systems and ensure they’re always working optimally. If left unchecked, debris, oils, scale, and particulates can build up, potentially leading to reduced flow rates or blockages. The frequency with which you clean your pool filter will depend on the size and usage of the pool.

Our best cleaning practices include:

Cleaning or replacing the filter cartridge, if one is used in your filtration system
Inspecting valves and seals for signs of wear and damage
Checking pump components for obstructions
Strain large bits of debris manually to prevent them from entering the filter
Testing that the pressure gauge is working correctly and producing accurate readings
Make sure the pool is fully enclosed during the winter months to avoid additional strain on the filter
Arrange for a professional cleaning service at regular points throughout the year

2. Backwash the Filter for Easy Cleaning

One of the most straightforward methods for cleaning a swimming pool sand filter involves reversing the flow of water through the filter. This is known as ‘backwashing’, and helps flush out any trapped contaminants. If you notice signs of a blockage, then it could be a good idea to try backwashing your filtration system. It’s often best to check your pool for debris after periods of extreme weather, although a blockage can also be indicated by an abnormally high pressure gauge reading.

The typical backwash process for a sand filter follows:

The first step in any pool maintenance is to switch off your swimming pool pumps.
Next, turn the valve on your pump to the backwash setting. This might have a slightly different name depending on the make.
Open the waste valve and attach a hose to the backwash port.
Turn on the pump to start the backwash and keep it running for around a minute, or until the water leaving the hose starts to run clear.
Collect the dirty water in a bucket and dispose of it via a drain.
Turn your pump to the rinse setting to remove any small debris still left in the system.
Finally, run the pump on its regular setting for 15-20 seconds and then return all components to their normal positions.

If your pool water still appears dirty after a minute of backwashing, it’s still recommended to stop the pump and follow the rest of the instructions (rinsing etc). Afterwards, simply go through the backwash cycle again. If the pool filter hasn’t been cleaned for an extended period, it may take a few washes to clear all the debris from the system.

3. Adjust Chemical Treatments

Chemical treatments are an essential aspect of your pool maintenance routine. The chemical balance in your pool must be carefully monitored to ensure the water is clean and safe. This helps extend the lifespan of the filtration system by removing oils and other potentially damaging substances. The best chemical treatments for your pool will be dictated by its construction materials and intended use. As such, it’s often recommended to get advice from your swimming pool installers or the pool manufacturing company.

A lack of chemical treatments or chemical imbalances can lead to a buildup of algae and bacteria. This can affect the filtration system by preventing the smooth flow of water, and can’t be easily removed through backwashing and rinsing. A strong smell of chlorine near a pool is often a clear indicator of a chemical imbalance. ‘Shock treatments’ using specialist chemicals can be used to correct this status. However, you must follow the instructions and recommendations on the product. For instance, our Aqua Floc (Liquid Cationic Floculant) is designed to be used in low pH water conditions.

4. Regular Testing and Monitoring

Even if you aren’t using your pool or use it infrequently, you still need to conduct maintenance checks to ensure the filtration system needs to be cleaned or repaired. Additionally, it’s important to determine whether the other systems that support the function of the filter are working as they should. For instance, if the pool skimmers are faulty, then this could lead to large debris interfering with the filter.

An inefficient filtration system will also be working harder than it needs to and costing you money as a result. Monitoring all the systems in your pool regularly will help keep costs down throughout the year.

Swimming Pool Maintenance Tips for Our Filter Products

By understanding how each Waterco filter works and the best way to maintain it, you can preserve performance, protect your investment, and avoid costly downtime when it matters most. Waterco’s Ecopure media is created from recycled glass filters.

Waterco Micron Side Mount Filters

Waterco’s range of micron commercial filter tanks is manufactured from fibreglass and the highest-grade non-corrosive materials. The inner shell of fibreglass-reinforced polyester resin is overwound with fibreglass filament. A vinyl ester resin coating is available for added durability. The Micron SMD filters are designed to last for many years without the need for repair, although some maintenance upkeep is necessary.

In one of our past projects, our solution included five SMD1800 Micron commercial sand filters and four 7HP BH5000 cast iron pumps to support the 800㎥ volume of the main pool. The Saltdean Lido for outdoor recreational swimming also featured a children’s splash pool (17m long), in which one SMD1800 Micron commercial sand filter and two Hydrostar 6HP pumps were installed.

Key Features:

Constructed for durability and UV resistance
Equipped with a top-quality six-position multiport valve with sight glass and quick-connect half unions
Ideal for medium to large domestic pools and commercial installations
Hydraulically balanced laterals maximise water filtration and flow
Large base for stable mounting
2.5, 4, 6, and 8 BAR models available

Maintenance Tips:

Backwash regularly, typically once a week during peak use or when pressure rises by ~10 psi
Inspect the multiport valve and laterals every 6–12 months for signs of wear
Rinse after backwashing to reset the filtration media
Annually check for leaks or pressure anomalies around the tank collar and valve union

Best suited for:

Heavily-used residential pools
Hotel or holiday park pools
Pools with high bather loads or exposed to debris (e.g. outdoor pools near trees)

Waterco Micron Bobbin-Wound Top Mount Filter

These filters are the latest in fibreglass winding technology, featuring continuously winding strands with tension controls. Additional Waterco digital controls ensure consistent performance levels. Models are available ranging from 500-800mm inner diameter, each with corresponding bed depths. The SM bobbin wound top mount filter doesn’t feature any welds, seams, or linings which can be likely to attract corrosion.

Key Features:

Compact design with a top-mounted valve for easy integration into tight plant rooms
Bobbin-wound fibreglass tank offers high strength with a seamless finish
Internal air bleed system
Filter max working pressure of 2.5 BAR
Suitable for most standard residential pools

Maintenance Tips:

Check pressure gauge weekly and backwash when indicated
Use a mild descaler annually to clean internal pipework and multiport valve internals
Monitor the condition of the diffuser and spider gasket, especially if heavy backwashing has been required

Best suited for:

Domestic pools with limited plant room space
Refurbishment projects with restricted access
Seasonal-use pools (e.g. holiday homes or summer-only use)

Waterco Monobloc Sand Filters

As a modern sand filter, the monobloc combination from Waterco is capable of catching even the smallest dirt and debris. This filter can be fitted in pools ranging from 36㎥ to 81㎥, varying depending on the model number (T400, T450, T500, T600). Furthermore, the monobloc sand filter combines with the Aquamite pump for a complete pool solution.

Key Features:

Abrasion-proof, thermoplastic tank
Easy-to-use multiport valve
3.5 BAR pressure rated
Hydraulically balanced laterals
Bed depth of 250mm
Option for top and side mounted valve

Maintenance Tips:

Regular backwashing to clean the sand or glass (this can simply be done by turning the multiport lever to the ‘backwash’ position)
Replace filtration media roughly every 3 years
Inspect sight glass regularly to check its clarity

Best suited for:

Domestic use swimming pools
Reliably managing a commercial facility
Outdoor pools that experience a range of weather conditions throughout the year

Waterco Hydron Split Tank Filters

The ideal option for retrofitting in commercial settings, this filter can be easily assembled on site as it comes in two halves. These are joined together seamlessly using an o-ring and bolted flange. Its high rate of water flow distribution makes it suitable for large commercial applications, and maintenance is minimal due to the latest gel-coated fibreglass technology.

Key Features:

Lightweight compared to steel counterparts
Chemical resistance to rusting, corrosion, and damage from various water treatment solutions
‘Fish bone’ lateral system for superior water flow distribution through the filter bed
Parallel inlet and outlet ports help maintain external plumbing integrity
Optional lateral manhole and sight glass configurations

Maintenance Tips:

Monitorthe internal air release valve for blockages
Clean and test the sight glass regularly to ensure accurate backwash visual cues
Always use the correct grade of filter media to prevent channelling and maintain bed depth

Best suited for:

Pools with large turnover demands
Multi-pool commercial sites
High-bather-load facilities like leisure centres and school complexes

Choosing the Right Filter for Your Pool

The filter you choose must be sized appropriately for the pool and contain elements that work effectively. If not, this can compromise the effectiveness of the filter by resulting in blowby (particles slipping through the filter) and potentially cause damage to the system.

Pool Type	Recommended Filter	Maintenance Level
Domestic (standard)	Micron Top Mount	Low
Domestic (high use)	Micron Side Mount	Moderate
Compact Plant Room	Bobbin-Wound Top Mount	Low
Commercial/Public Pool	Micron Commercial	Higher (Automated options help)
High Flow/Heavy Use	Hydrostar Plus	Moderate to High

Still not sure which filter is right for your pool? There are many factors to consider beyond just maintenance. Our professional team are available to advise on the best solution for your pool, focusing on cost-effectiveness and style.

Minimise Maintenance Costs With Paramount Pools

All swimming pool systems and features must be installed and serviced by a qualified technician to guarantee safety and extend lifespans. Whether you’re maintaining your home pool or multiple commercial installations, proper filter care will make a world of difference to your pool experience.

The best maintenance schedule for your swimming pool filter will depend on a range of factors. This includes the type of filter, pool features and dimensions, how your pool is used, and its location.

At Paramount Pools, we supply far more than just filters. Our range of swimming pool equipment includes pumps, stainless steel fittings, heating, lighting, pool swim jets, and cover cleaners. Find one of our dealers near you to get started, or you can get in touch with us directly if you have any questions about proper swimming pool maintenance.