In South Africa, unlike those poor Game of Thrones people who are continually preparing for the coming of winter, we are excited because summer is most definitely on the way. Longer days, plenty of sunshine and temperatures in low 30s all signal the start of our very favourite season.

Summer in South Africa is when we braai, boost our vitamin D levels and make good use of our swimming pools. However, summer is also the time of dramatic thunderstorms. Thunderstorms bring much-needed rain, so we have to love them, but they can also cause one of the biggest headaches of the entire summer season – a green pool.

Why Do Thunderstorms Give You A Green Pool?

Essentially, there are two main reasons for this annoying phenomenon. Firstly, although rainwater itself isn’t bad for your pool, the sudden addition of extra water can dilute the existing chemical levels. This can result in the dreaded green pool.

The other reason is all a bit science-y. As you know, thunderstorms are made up of lightning and thunder. Apart from giving us a spectacular, if somewhat scary, show, lightning creates nitrogen in the atmosphere. The accompanying rain washes this nitrogen down to the ground – and into your pool.

Now, nitrogen is like catnip for plants – they love it. Algae is no exception, so when nitrogen washes into your pool during a thunderstorm, the algae gets very excited. Even the best-maintained pools have some algae in them, although they are invisible to the human eye when their numbers are small. But after feasting on the nitrogen so thoughtfully provided by the thunderstorm, they quickly bloom and multiply until their numbers are big enough to give you a green pool.

How Can I Fix My Green Pool?

As the saying goes “an ounce of prevention is worth a pound of cure.” This basically means it’s much quicker and easier to keep your pool as algae-free as possible than it is to fix a post-thunderstorm, algae-infested green pool. So make sure your water is properly balanced at all times, keep sanitiser levels (such as chlorine) constant, and use an algaecide regularly.

However, if you do find yourself faced with a depressingly green pool after a storm, there are two key things you can do to help get it back to its usual happy blue as quickly as possible:

  • Shock it with chlorine – do this as quickly as possible after the storm before the algae really have a chance to take hold. Just remember not to use your pool for 24 hours after you’ve shocked it.
  • Dose it with algaecide – this helps starve your pool water of oxygen, which then makes it impossible for algae to survive.

If you’d like any professional advice on restoring your green pool back to blue, why not chat to the friendly experts at Pool Spa & Filtration Supplies. We have everything you need to fix your pool so you can enjoy a sparkling summer!