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Tips for winterising your pool

Ensuring your swimming pool is well maintained is a year-long job, and that includes harsh winters. You need to make sure that your pool is protected during the off-season so that when you come to open it up again in the spring, it’s ready to use without any unexpected repairs to deal with.

But there are several steps to check in order to winterise your pool correctly, which involves more than simply putting a cover on and hoping nothing gets damaged. In this blog, we’ll provide our top tips for winterising your pool to keep it in the best condition.

Shock the pool

Shocking the pool refers to adding a higher quantity of chlorine to the pool to kill off any bacteria and contaminants that might remain in the water. It sanitises the pool and doing this before you shut it down for winter will prevent the growth of harmful bacteria. It’s worth doing this two or three days before you plan on closing your pool down, so that the water can return to its normal chlorine levels before you start the winterisation process.

Remove leaves and debris

The first step to winterising your swimming pool is to get it as clean as possible, which means removing all leaves, twigs and debris that has collected in the water – a common problem with garden pools that are surrounded by foliage. Leaves will not just contaminate the water and increase bacteria, but the tannins in the leaves will also stain the pool’s surface if they’re left to decompose in there over winter.

While you’re removing leaves, it’s a good time to clean the rest of the pool too, so use a pool brush and a telescopic pole to scrub the walls and the floor as much as you can to remove any debris, algae spores and grime that has settled. Once you’ve cleaned off as much as possible, make sure as much dirt and algae that has been kicked up is removed before moving onto the next step.

Add a winter algaecide

Once any materials have been removed, you should add an algaecide which will protect your swimming pool from developing algae while it’s not in use. The quantity you add will depend on the type of cover you use – an impermeable cover will only require one dose while a porous cover will likely need two to be effective. Make sure you distribute the algaecide around the pool evenly rather than just in one corner.

Balance the water

The key to ensuring your pool stays clear is maintaining the right levels of chemicals in the water, something which can often be overlooked during general maintenance. With a little bit of care and attention prior to closing down your pool, you can avoid being faced with green pool water in the spring. Test the pH level and the alkalinity of the pool with test strips or a testing kit, so you can adjust it to the right level. You want the pH of your water to be between 7.2 and 7.6, and the alkalinity between 80ppm and 120ppm.

Lower the water level

It’s a good idea to lower the water level to below the skimmer, so that no water gets into the pump or filter system when freezing temperatures hit. You don’t want to completely drain the pool because this can lead to other problems, such as damage to the pool lining, or even some covers not working properly. But lowering it to the just below the skimmer will keep everything in good working order.

You can clear the pool lines by using a wet and dry vacuum to blow any water that’s sitting in the pipework back into the pool. Backwashing the filter and pump will reduce the chance of algae growing over the winter in the filter. After you’ve done this, and the level of the water is around 30cm below the skimmer (or 10cm lower if you’re using a cover that sits on the surface of the water) you can turn off the pump and position the valve to winter.

When the pump is switched off, drain all the pool equipment to prevent damage if the water freezes. This means checking there’s no water in the pump, filter, heater, UC system and any other essential elements that could freeze.

Remove and clean accessories

Remove any accessories in your pool, such as ladders, rollers and any other items that you use in your pool. It’s a good time to clean these items before storing away for the warmer months, especially if you have a saltwater pool as the salt will cause the accessories to rust or become damaged. It’s best to store any accessories inside over winter to prevent damage.

Deal with any signs of disrepair now

If you spot any signs of disrepair while cleaning your pool, it’s important to have them checked and resolved before winter. For example, cracking in the pool lining or algae growth that suggests the filter isn’t working correctly can be a sign of a problem that will only get worse with time. Resolving those problems now before leaving your pool will minimise the cost and amount of time needed to repair it in the future.

Cover the pool

The last step of winterisation is to cover the pool, including the pool pump. There are various pool covers you can buy to suit your particular type of pool, so make sure you choose the right one for your needs. Depending on which one you choose, you might need to continue cleaning the debris off throughout the winter season. Have an above ground pool? Inserting a pool pillow in the centre of the pool will prevent snow and ice from burying the cover under the water.

When to close your pool

It depends where you’re based as to when the best time to close your pool is, but if the temperatures in your area have dipped below around 10 degrees, or if the weather conditions are harsh, it can be worthwhile preparing your pool so you’re not dealing with it in the wind and rain. In the UK, this may be as early as late October or in November when the temperature tends to be a lot lower.

It’s important to winterise your pool before the temperatures dip, but if you’re a little late, carrying out the process now will prevent any unnecessary damage over the remainder of the winter season. A swimming pool is an investment you’ve made into your home, so it’s worth taking the time to protect it to keep it in great condition for as long as possible.

Need some further advice? Contact us – our team is always on hand to answer any queries you may have and offer advice to keep your swimming pool in top condition.

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