1. Give the pool a thorough cleaning – Before you say goodbye to pool season for good, make sure the pool is given a thorough cleaning. Skim, vacuum, and brush the pool. If your pool has a lot of algae or silt you may want to bypass the filter and manually vacuum the dirt from the pool – this will prevent your filter from clogging.

Place the multiport filter valve on the drain to waste position (usually 2 pm, if viewed as a clock face) If you have a push-pull filter valve, or a cartridge type filter there is no easy way to vacuum to waste, except for cutting the pipe coming out of the pump and then reconnecting afterward. Brush the pool thoroughly. The pool should be as clean and clear as possible before covering it. You can purchase winter swimming pool enclosures at various online sources.

2. Pool plumbing should be winterized – Make sure you undertake these pool winterization steps before closing up the pool: with in-ground pools you should blow out the lines from the skimmer, through the equipment, and back to the pool. Once you're done, plug the lines at the pool. If you don't blow the lines, add Swimming Pool antifreeze to prevent cracking and breakage. Above-ground pool owners usually just need to disconnect the hoses to and from the pump and filter and plug the wall outlets.

3. Add winterizing algaecide and other floaters. – Don't add algaecide and shock at the same time. This could result in chlorine breaking down the algaecide.

4. Cover the pool – Once you've undertaken the steps above, now's the time to cover the pool. To prevent the cover from blowing off and debris getting in, a tight fit of your pool cover is essential. Your cover should not have holes or gaps where leaves and debris may enter. A mesh safety cover provides the highest protection.

Solid pool covers do not offer as much protection and require a siphon to remove rainwater or melting snow. Above-ground pool covers use a cable device to secure the cover around the pool. 

5. Sunbelt tips – If you're fortunate enough to live in an area where the temperature rarely dips bellowing the freezing level, many pool owners reduce the amount of daily filtration time and find the pool requires fewer chemicals. Covering the pool, even if not winterizing, will reduce cleaning and chemical and filtering demand even further.