August 21st, 2020 by Sarah Miles

Algae in swimming pools can form for several reasons: water being out of balance, sunlight, heat, poor circulation or filtration etc. Sunlight causes algae to photosynthesise and multiply rapidly so, without intervention, you can end up with a pool full of the stuff in no time at all.

The most common type of algae in a pool is green algae. It floats on the water and can attach itself to the pool walls and floor. It is generally slimy and unpleasant and you definitely don’t want to swim in it. While it can be tricky to get rid of, it’s not impossible.

1. Vacuum the pool

As with most jobs of this type, preparation is the key to a successful outcome and that’s going to require a little manual labour. Using a pool vacuum, go over the floor and walls of the pool. This will remove some of the surface algae and bypass the filter, which could circulate contaminated water back into the pool.

2. Get brushing

Using a pool brush on a pole, scrub the surface of the walls and floor of the pool to release the stubborn algae, that you weren’t able to remove with the vacuum, into the water (it’s going to look worse before it looks better). Pay special attention to the corners where it can be harder to get into the tight space.

3. Balance the water

The treatment you put into the water will be more effective if it has the right pH level first. Use a test kit and then treat it to achieve a pH level of around 7.2-7.8. High alkalinity will inhibit the pool shock that you’re going to apply in the next stage.

4. Shock the pool

Shocking is the process of adding chemicals to your pool to kill algae, bacteria and other pathogens. For this, we use calcium hypochlorite, also known as chlorine shock or granular chlorine. Add the right amount of chemical for the volume of water in the pool (see the instructions on the packet). For outdoor pools, it can be advisable to do this after the sun has started to set as sunlight will eat up most of the chlorine before it can work on the algae. That said, some products are designed to survive the effects of sunlight.

2.5KG Chlorine Granules

Chlorine granules help keep your pool water clean and hygienic

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5. Run the filter

The chlorine shock will turn your water a cloudy blue as it kills the algae. Running the filter for at least 8 hours should clear this up.

6. Test again

Once the process is complete, you will need to test the water again to check the pH level. Make sure it is correct before allowing anyone back into the pool.

7. Clean or change the filter

You may have cleared the algae from the pool but there could still be particles of it in the filter and, if left alone, could re-contaminate the water. Remove and deep clean it or simply change the filter for a new one.

Prevent future outbreaks

Now that you have put in all this hard work to get your pool looking fresh and clean, make it harder for algae to develop again by regularly using an algaecide. Just a small amount each week can maintain your water and save you from having to repeat the removal process. When it comes to algae, prevention is much, much more effective than the cure, so those weekly doses will save you a lot of trouble in the long run.

5L Hot Tub and Spa Algae Remover

Pro-Kleen Algae remover eliminates and prevents the growth of algae in your pool, helping to maintain healthy, clear clean water.

Price: £21.95

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