How to clean swimming pools after a storm or flood

Heavy rains, winds and natural disasters like floods can destroy the cleanest and most well maintained swimming pool, leaving the owner in disbelief of their tropical oasis. Severe weather can sweep dirt and debris into your pool, while floods can add an even larger amount of mud, silt, and contaminants.

At Mr Pool Man, we know it seems challenging to maintain a healthy pool after a storm or flood, so we have compiled these easy-to-follow tips below for returning your pool water back to crystal clear, no matter how dirty your pool might look.

It is essential to assess the pool and associated electrical equipment prior to commencing any work to ensure the safety of yourself and others. Once the floodwater / storms have receded the fence is the first point of inspection to ensure the safety of the pool has not been compromised. Restrict the area if there is any concern with electrical or fencing aspects until a professional can deem these as safe.

Many of the after effects we see on swimming pools is -

  • Debris, silt and soil washed into the pool
  • Phosphates and contaminants introduced into the water
  • Dilution of chemicals and salt levels causing water imbalance


Steps on how to clean swimming pools after a storm or flood -

  1. Do not drain your pool, the pool may pop out of the ground due to ground water
  2. Clean out as much debris as possible. Debris will add large amounts of organic matter to the water, which in turn will cause issues with algae and chlorine residual. The sooner rubbish is removed from the pool; the sooner clean-up can begin.
  3. Clean skimmers, main drains and pump baskets.
  4. Call an electrician or pool service provider, in the event the breaker doesn't reset.
  5. Check the pressure gauge on your filters: Turn off your equipment and ensure you clean your filters regularly during the clean up phase.
  6. Shock the pool with chlorine: Due to heavy possible contaminants, you may have to double the recommended dose. Do not swim in the pool for at least 48 hours.
  7. Run pool equipment 24 hours a day until water returns to its normal clear state. Continue to monitor the filter's pressure and chlorine levels.
  8. Add a floc or clarifier to aid in settling debris to the floor
  9. Vacuum the debris, silt and contaminants to waste
  10. Turn on and leave on the pump/filter till water balance has been achieved. From now, much of the debris should have been removed from the water. Although still cloudy, the filter is the easiest way to clean up the water.
  11. Use a clarifier one last time when the water is balanced
  12. If there is no positive change to your pool, contact a local service provider. Contacting them now will get you help as soon as possible since most companies take weeks to address your situation.


Cartridge Filter maintenance

When was the last time you cleaned your cartridge? If it was a while ago, take your cartridge out and give it a good hose down. Tip: If you are after a thorough clean, soak your cartridge in a tub of clean water with a cup of filter cleaner overnight. Follow this by a good rinse with your garden hose the next day.

After adding any flocculants or clarifiers to your pool debris will trap within your filter, but if not cleaned after a day or two of using these chemicals can cause the filter to permanently clog and reduce the life and performance of the filter element. Ensure the maintenance of the filters is more than normal during a storm or flood clean up phase.

Clarifiers, Crystal Cubes and CAN be used with cartridge filters ensuring that they are cleaned to avoid issues!


Flocculants & Clarifiers

Cloudiness is caused by small particles suspended in the water, these particles are smaller than 2 microns and will not get caught within the filter system. These particles are commonly negatively charged.

To remove these particles and restore clarity in the water you need to add a flocculant / clarifier to the water which are positively charged and bond the suspended debris together. Some debris that floccs together will float to the surface and capture within the skimmer / filter, the majority of the debris will sink to the pool floor where it is recommended to be manually vacuumed out of the pool via waste.

A key point to note is that flocc works more effectively with higher pH, so test your pool prior to adding clarifier or floc and ensure that the pH level is a minimum of 7.8. You can also raise the pH by adding Buffer to the pool which will also raise the Total Alkalinity.


Avoid emptying pools!

Except for the most severely affected, almost all swimming pools and spas can be brought back to life after floods, storms and fire without the need to drain the water. In that instance it should always be left to a professional – a pool owner should never drain their own pool.


All chemicals should be used in line with the instructions on the rear of the label. Please contact your pool professional for further advice if unsure.


Zodiac Ezy Clarifier - Pool Spa Floc Chemical Clear Cloudy Green Water

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Zodiac Phosphate Remover 1L - Pool Spa Algae Staver Black Spot Chemical

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Zodiac Power Clarifier Granules 2KG - Pool Spa Floc Chemical Clear Water

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Post author:

Tom Hintze

Head of eCommerce & Operations at Mr Pool Man,
Co-Founder at Water TechniX


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