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How to Shock a Pool
If your pool water is starting to look a little cloudy or you feel like something is just a bit “off”, it’s likely time to shock your pool. Whether you're a first-time pool owner or a seasoned pro, shocking is an essential part of keeping your swimming water clean, clear, and safe.
If you’re thinking, huh? Shock my pool? Worry not, our handy guide will walk you through the exact steps to shocking your pool, including when to do it, which shock to use and the correct application technique.
Before we get to the finer details, in short, to shock a pool:
For optimal results, retest before swimming and always shock in the evening to minimise UV degradation. Follow the manufacturer's instructions carefully.
Shocking your pool is essential as it removes invisible contaminants that regular chlorine levels can’t always break down, such as bacteria, sweat, sunscreen, and algae spores.
You should shock your pool to:
Even if your water appears fine, regular shocking helps maintain proper sanitation, especially during peak swimming season.
Let's break down some of the earlier steps into easy, achievable processes to help you maintain the ideal pool levels.
Using pool test strips, a comparator or a photometer, check chlorine, pH, and stabiliser levels. Ensure the pH is between 7.2 and 7.6, as this will enable your shock treatment to work effectively.
It may seem overwhelming, but checking the dosage you require is a simple process. Simply take your pool’s volume in litres and then follow the instructions on your chosen shock product.
It’s essential to note that additional shock treatment may be necessary if algae are present.
Pre-mix the shock treatment in a container before adding it to your pool. Then, with the pump running, Chlorine shock is best for algae and bacteria, while non-chlorine shock is ideal for regular maintenance/oxidation, as it does not kill algae like chlorine.
Once this is done, run circulation for at least eight hours and do not get into the pool until you have retested with your strips or photometer.
For routine maintenance, shock the water every 1-2 weeks to keep it crystal clear.
This largely depends on chlorine levels, specifically when the free chlorine level returns to 1–3 ppm and the pH is between 7.2 and 7.6 before swimming. This usually takes 12–24 hours, but non-chlorine shock treatments allow swimming after just a few hours. Just ensure you test first with monocopper sulphate test strips.
You could, but it’s not ideal. Shocking in the evening or at night prevents UV rays from breaking down the chlorine before it can do its job. To save time, energy, and costs, consider waiting until sundown or until the UV rays are at their lowest.
Shocking your pool is one of the fastest ways to restore clean, safe swimming conditions, but doing it correctly is crucial. From choosing the proper shock treatment to understanding your pool’s specific needs, 1st Direct Pools is here to help.
With over 20 years of experience, expert advice, and fast UK delivery, we make it simple to keep your pool in top condition. Browse our pool shock treatments and contact our team of experts for any help.
At 1st Direct Pools, safety always comes first, so we advise against mixing different chlorine types or combining chlorine and bromine in the same water. Also, avoid adding pool shock treatment via the skimmer if tablets or a feeder are in use, and shock in the evening to reduce UV degradation.
