October is when an outdoor pool stops being used and starts being at risk. Water sitting in pipework can freeze and crack it, and a pool left unbalanced turns green long before spring. Closing it down properly now is a small job that avoids a large repair bill in April.
Here is how to winterise a UK pool, step by step. If you would rather it was done for you, our team covers this every autumn.
Closing an outdoor pool, step by step
- Balance the water. Correct the pH, alkalinity and chlorine first, so the water is stable while it sits.
- Give it a deep clean. Brush the walls, vacuum the floor and empty the skimmer baskets, so nothing is left to rot over winter.
- Lower the water level. For a typical UK winterisation, drop the level just below the skimmers and returns.
- Protect the plumbing. Drain the pump, filter and pipework, or use pool-grade antifreeze, so nothing freezes. This is the step that saves the expensive damage.
- Add winter chemicals. A winteriser treatment keeps the water clear and holds off algae until you reopen.
- Fit a winter cover. A debris cover keeps leaves, dirt and frost out and makes spring start-up far easier.
Should you fully drain the pool?
Usually not. An empty pool can lift, crack or distort over winter, and refilling wastes a lot of water. A partial winterisation, with the level lowered and the plumbing protected, is the safer route for most UK pools.
Indoor pools are different
An indoor pool is built for year-round swimming, so it does not get winterised in the same way. You keep it running and heated through the colder months, simply adjusting the temperature and ventilation to suit. If anything, winter is when an indoor pool earns its keep.
Frequently asked questions
When should I close my pool for winter? Before the first hard frost. In most of the UK that means October, which is why now is the moment to act.
What happens if I skip it? The common outcomes are cracked pipes, a damaged pump and green water that takes weeks and a lot of chemicals to clear in spring.
Can you winterise my pool for me? Yes. Our team winterises pools across the region every autumn, so your pool is protected without you lifting a finger.
Do I need a special cover? A proper winter debris cover is worth it. It keeps the water cleaner, protects the finish and makes reopening quick.
Protect your pool this October
A well-closed pool reopens clean, clear and ready to swim. Book a winterisation with our team, or ask us to check over the pool before the cold sets in.
