Relaxing in the swimming pool is great in warm weather. When the temperature drops, though, you’ll likely need to take steps to winterize your outdoor pool. It’s important to understand the winterization process so you can make sure it’s done right. Otherwise, your next pool inspection might reveal costly damages.

Do You Need to Winterize Your Pool? 

If you live in an area where temperatures drop near freezing and have an outdoor pool, winterization is a process you shouldn’t avoid. It is the best way to protect the investment you’ve made in your pool. Just as freezing temperatures can burst your home’s pipes, they can also destroy your pool’s plumbing and other equipment. Even if temperatures don’t stay cool for very long, a small accumulation of surface ice can tear your lining. 

If you live in an area that doesn’t freeze but is still too cold for swimming outside during the winter month, you should winterize your pool as well. Your pool will go several months without use, and lack of winterizing or preventative maintenance can wreak havoc on your pool’s health. 

Closing the Pool For the Winter

Closing The Pool For The Winter WIN Home Inspection

When it’s time to winterize your pool, there are a couple options available. You can go through a winterization process focused on closing the pool entirely, or you can take steps that allow you to leave it open. Since most people don’t use their outdoor pool at all during the colder months, closing things down is typically the option. 

If closing the pool is right for you, take the following steps:

Correct the Water Chemistry

Make sure your water chemistry is appropriate. The pH balance, chlorine levels and other chemicals in your pool dictate your water's health over time. You should use a pH strip to test pH levels, and use sodium carbonate to raise levels, or sodium bisulfate or muriatic acid to lower levels until your pH is in the 7.2 to 7.6 range.

Remove Unnecessary Items

Remove all ladders, cleaners, wall fittings and skimmer baskets from the pool over the winter.

Clean Up!

Make sure you skim, brush and vacuum the pool before shutting everything down for the winter.

Get on Level

Reduce the water level of the pool, so that it sits below your skimmer.

Drain and Winterize Equipment

Drain all equipment that has water going through it. This includes your filter, chlorinator, pump and other mechanisms. You'll need to use pool antifreeze on the pipes and lubricate the o-rings as well.

Shock the Pool

Shock the water a few days before closing your pool down. Adding this high level of chlorine will kill off bacteria and other unwanted organisms.

The Final Touches

You’ll need to use algaecide before closing everything down, but this should be added separately from shocking the pool. Once you complete this, apply the pool cover with the following steps:

  • Spread cover over entirety of pool. Be careful not to damage or snag the cover. The "caution" label should face up.
  • Adjust the cover so there's only 10-15 inches of overlap at all points of the edge.
  • Use weighty objects — such as sandbags or buckets of water — to hold straps in place.
  • Mark anchor points and install anchors. Center these on each wall.
  • Attach springs to the straps, then place them on the anchors.
  • Continue installing all anchors and then double check to ensure they're secure.

When you take the time to winterize your pool correctly, you’ll make life much easier when it’s to get your pool ready next summer. 

Preventative Measures When Leaving the Pool Open For the Winter

preventive pool maintenance for winter WIN Home Inspection

Even in areas where freezing temperatures are common, some people don’t close their pools in the colder months. While this may seem to defeat the purpose of winterizing your pool, it’s a fairly common practice.

If you opt to go this route, you need to take the following steps: 

Prevent Freezing

Install a freeze sensor to prevent potential damage. Use pool antifreeze on the pipes and pumps that feed the water features for the same purpose. Leave all valves open and allow the pumps to keep running.

Stay on Top of Cleaning

Even if you don’t shut down your pool, winter is still coming. Stay on top of your cleaning regimen to deal with excess leaves and debris.

Maintain Appropriate Chemical Levels

You must maintain the pH level and other chemicals in your pool at appropriate levels regardless of whether you're swimming in it or not. Otherwise, you might end up with a murky cesspool of water.

Avoid Common Winterization Mistakes

When it’s time to winterize your pool, what you don’t do can be as important as what you do. Well-meaning people sometimes work hard to protect their pool only to discover that damage occurred due to a mistake. Whether you’re closing your pool for the winter or leaving it open, make sure you avoid these winterization mistakes: 

  • Going too easy on filtering: When preparing to close your pool, run the filter for at least 24 hours during the winterization process — 48 hours if the water is very dirty. 
  • Ignoring manufacturer recommendations: Manufacturers include instructions on managing water levels during winter. 
  • Using a cheap pool covering: If you opt to cover up your pool, invest in a quality cover. 
  • Leaving recreation equipment in place: If you have a slide or diving board, remove and store it for the winter.
  • Not properly securing cover: You need to attach straps and make them tight. The edge should be flush and tight with deck surface. 

Secure Pool Cover WIN Home Inspection

When you winterize your pool, specialty pool antifreeze can be a big help. If you do use this route, make sure to follow the manufacturer instructions to the letter. You should not add swimming pool antifreeze to the chlorinator, filter, pump or heater.

Don’t Wait to Take Proper Steps to Prepare Your Pool For Winter

It may not be fun to admit, but procrastination is part of human nature. Unfortunately, this can lead to serious issues if you don’t properly winterize your pool before winter hits. Damage to your lining, pump, filter and plumbing can cause thousands of dollars in necessary repairs. Taking proper steps to care for your pool — including appropriate winterization — will help avoid these costly issues. 

Just because it's time to winterize your pool doesn't mean you have to do all the heavy lifting. Contact WIN Home Inspection today for a pool or spa inspection to check for underlying damage before or during winter. Call (800) 309-6753 or reach out at to speak directly to one of our experts.