How to Prevent and Remove White Water Mould


Owning a swimming pool is a wonderful experience with an array of exciting opportunities. Unfortunately, these opportunities also involve the maintenance of the pool’s water chemistry.

But there’s no need to despair, as it is fairly easy to maintain a clean, healthy swimming pool, which will avoid any uninvited issues that may prove tedious to rectify.

This guide will guide you through the process of preventing and treating white water mould to help you maintain a clean and safe swimming pool.

If you would like to stock up on your swimming pool maintenance kit and accessories, you can find these instore and online at 1st Direct Pools. If you’re looking for a new cover, you can use a swimming pool cover calculator.

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What is White Water Mould?


White water mould is a fungus that can form in a swimming pool. The mould takes on a white, mucus or torn up tissue-like appearance. The mould is not harmful to humans, but it is unsightly and can clog your equipment.

The mould will deplete the oxidiser levels of the pool. It can be highly resilient to both chlorine and bromine, which can usually work wonders when deep cleaning swimming pools.

This resistance to chemicals will make the task of treating white water mould difficult. Recontamination can easily be initiated even after the mould has been removed, which is why working to prevent the issue from development is crucial.

It is worth noting that UV rays are highly effective in killing white water mould; indoor pools are much more prone to developing the mould in comparison to outdoor pools.

Feet splashing in a pool

How to Prevent White Water Mould


The easiest way to treat white water mould is to prevent it altogether. You can easily stop the spread by following these simple steps:

Clean the Pool

Every week, the surface of the pool should be brushed and cleaned. Cleanliness is a poignant factor when preventing fungal issues from developing.

UV Exposure

UV rays help to kill white water mould. If possible, ensure that your pool and accessories are exposed to as much sunlight as possible.

Clean the Pool Filter

The filter should be cleaned with chemicals regularly to prevent the fungus from establishing itself within your swimming pool systems.

Clean the Pool Tools

It’s important to include the pool’s accessories such as any maintenance equipment and toys that are used within the pool, as this will prevent any future contamination.

Any brushes, hoses and pool vacuums involved with the maintenance of your swimming pool should be thoroughly cleaned after every use.

If the tool begins to develop a fungal growth, it can easily be transferred to your pool the next time they are used.


Check the Pool’s Water Chemistry


The chemicals that are used to ensure a clean, safe swimming environment should be regularly balanced. Doing this will not just prevent white water mould but it will also avoid any other bacterial or erosive issues.

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How to Treat White Water Mould


If your pool has already been afflicted with white water mould, then you can follow our advice on how to successfully remove the fungus.

Remove the Mould and Deep Clean

When instigating the removal of the mould, you will need to effectively remove any visible trace of the mould and clean all of the affected areas.

Cleaning should include any items that may have come into contact with the mould during the cleaning process, such as:

- The pool ladder
- Pool toys
- Floats
- Pool fittings
- Underwater lights
- Maintenance equipment

Swimming pool lanes

Shock Dose the Swimming Pool

The next step is to shock dose the water with a quadruple dose of calcium hypochlorite (otherwise known as chlorine shock). Shock dosing your swimming pool is highly recommended to be carried out weekly.

When you shock dose a swimming pool, you are essentially adding a higher amount of chlorine, or other pool sanitisers, which will drastically raise the chemical level of the pool and kill off any bacteria.

Once you have shock dosed, the filtration system should be continually run until the water is clear and the chlorine or bromine levels test high. Running the circulation pump will also prevent any staining during shock dosing.

swimming pool shock treatment

Clean the Filter

Before chemically cleaning the filter, calcium hypochlorite should be backwashed straight through the skimmer.

The treatment will need to be carried out quickly and effectively. White water mould can remain a contaminant even after treating the surface of PVC plastics (common for above-ground pools).

Avoiding Recontamination

White water mould can recontaminate long after its initial appearance.

It can especially reappear after it has been eradicated if a regular cleaning schedule is not maintained. The smallest of quantities can easily lead to the redevelopment of white mould.

If you require more support in dealing with white water mould, please do not hesitate to contact our team, here at 1st Direct Pools. Our experts will be happy to help assist you with more information and advice!