End of season care for your swimming pool

Summer is all but over and pools will be used less and less in the coming weeks. So whether you have an in-ground or hard sided above ground outdoor pool, now is a good time to start thinking about closing it down for the winter season.

Woking based BTU Pools (you’ll find us at Wyevale Garden Centre), one of Surrey’s leading swimming pool companies,  passes on some great advice for anyone with outdoor in-ground pool or hard sided above-ground pools. You can either ‘winterise’ your pool  yourself if you feel confident enough or else book now and get an experienced pool company to undertake the process for you.


The first thing you need to do is to get the pH and chlorine levels right before you do anything else to close down your pool.  So, make sure your water pH is within the range of 7.2 to 7.6. Then you need to get the chlorine levels to 6 to 10pmm. Use an unstablised Shock dose.  At BTU we normally recommend, brands like Swimfresh, Spafresh and Bayrol.

To get the product evenly distributed evenly around the pool – leave your pump running for 6-12 hours after you’ve added the treatment.

Next, you can add your Winterising Algicide.  This is a long lasting chemical designed to keep your pool free from algae over the winter months. Again, keep your pump running for 6-12 hours after adding it, to ensure the algicide is delivered to the whole pool.

Before doing anything else, check for leaks – it’s always worth doing this before you close your pool down – if you have an experienced maintenance company caring for your pool – they should automatically do this. Once you are confident there are no leaks, switch the skimmer valve off and drain the water down to 4-6inches below the bottom level of the skimmer (for in-ground pools). This ensures that you are allowing for any rainfall that will bring the level up, causing the pool to overflow over the winter.

Icing over in freezing months – you need to make sure that the pool walls are protected during the icy time of winter. Float some empty plastic containers in the pool to protect against ice expansion – place a few in the pool and tether them so they don’t all float into the same corner of the pool.


Take your summer cover off and give it a good wash down – take care not to do it too vigorously if it is old or delicate (you might want to consider getting a new one!) as it may split or deteriorate further. Dry it out and then fold and store or place it back on the roller with the winter storage cover.

Keeping leaves and debris out of your pool over the winter is critical, so you will need to put your winter debris cover on. Make sure it is tensioned well so that it doesn’t touch the water. Check and re-tension it a few days or a week after you put it on.

Safety is key – most normal winter covers are not safety covers, so make sure children and animals keep away from the pool area over the winter months if you do not have a safety cover.  Alternatively consider getting a safety cover for peace of mind.

Top tip for keeping your winter cover on a hard sided above ground pool. Weigh it down with water filled bottles.

Here’s a tip if you’ve got a hard sided above ground pool.  Weigh down the cover to avoid it being blown off,  by  filling water bottles with water and tying them to the cover.

Heaters, pumps and filters

Finally, once you have circulated the chemicals, drained down the water level changed over to your winter cover – it’s time to protect your pump, filter and heater so that they don’t freeze over winter. Simply remove the drain plug from each and let any retained water out.

Then, you can rest, assured that your pool is prepared for the winter months.

If you want any guidance or support or to purchase the chemicals for closing down your pool please, please call BTU Pools on 01483 727444, or drop by our Pool Shop at Wyevale Garden Centre, Woking – we’d be delighted to help. Please call also if you would like any advice or support in repairing, refurbishing or maintaining your pool.  We are currently taking bookings for our close down service.

by Levi Thatcher