When you own an in-ground pool in the Twin Cities, knowing when to close it is of the utmost importance. Performing a comprehensive swimming pool closing routine at the appropriate time helps ensure long-lasting pool performance and aesthetic appeal by preventing freeze-related plumbing and equipment damage.

When should you start thinking about getting your pool winterization underway? Here’s what you need to consider to determine the best time to close up your in-ground pool.

Pool Heater Use

Generally, outdoor public pools remain open from Memorial Day to Labor Day. But you don’t have to stop enjoying your backyard oasis quite that early. Most residential swimming pool owners close their pools on the third Saturday in September, which has been dubbed National Pool Closing Day.

However, if you use a pool heater, it can extend your pool season considerably. Usually, residential pools with heated water can stay open another three weeks or so past swimming pool closing Saturday.

Outdoor Temperatures

Even if you’re the polar plunge type, you can’t keep your Twin Cities swimming pool open once outdoor temperatures really start to drop. If you do, the water will freeze inside the plumbing system, and when it does, its natural expansion can damage the pipes, pump, and filter.

If you use a robotic pool cleaner, it should have instructions regarding the temperature at which it must be removed from the pool. Follow those instructions. If you don’t, the rapidly decreasing temperature of the water will end up damaging your robot.

It’s important to note, though, that the temperature at which you should remove your automatic pool cleaner isn’t necessarily the temperature at which you should start winterizing your pool.

Generally, the water temperature can drop a few more degrees — to around 65 degrees Fahrenheit — before you’ll need to plan for swimming pool closing. If you close up your pool while the water is still quite warm, it’ll have a higher risk of developing algae growth when it’s not in use. When spring rolls around, that’ll create more for you when it’s time to open your pool.

Tree Cover on Your Property

We all know autumn is leaf-dropping season, and if you allow a mess of leaves to land in your pool water, it’s a lot of work to get them out. So if your yard has a plethora of deciduous trees, you’ll want to start thinking about closing your pool as soon as those leaves start dropping.

If it’s still fairly warm outdoors and you’re not quite ready to stop enjoying your pool, consider using a retractable pool cover instead. Keeping it closed when your pool isn’t in use will help ensure your pool water remains as clean as possible with minimal daily maintenance. 

What’s the Absolute Latest Swimming Pool Closing Date?

Ideally, you should do your swimming pool closing by the second week in October. But if you want to stretch the pool season as long as possible, you should be able to safely keep it open until Halloween. We don’t recommend waiting any longer than that to winterize your pool.

For more detailed info, check out How Late Can You Extend Pool Season in Minnesota?

How Do You Close a Swimming Pool?

A thorough swimming pool closing routine involves several steps and quite a bit of work. If you plan on DIYing it, set aside an afternoon to get the job done. Here’s what you’ll need to do:

  1. Remove accessories. Detach, clean, and store anything removable, including the skimmer basket, diving board, ladders, rails, return fittings, and safety ropes.
  2. Clean the pool. Clean the pool as usual and test the water’s pH, total alkalinity, calcium hardness, saturation index, and chlorine concentration.
  3. Drain water. Drain water from the pool until the water level is about two to three inches below the skimmer to prevent ice damage. You can also apply a skimmer cover for extra protection.
  4. Shock the pool. Add pool shock to the water to prevent organic contaminants from growing throughout winter. If you don’t do this, you could end up with cloudy pool water or a pool full of nasty, green algae come springtime.
  5. Remove and clean pool equipment. Detach the filter, pump(s), chlorinator, and any hoses from the pool. Clean and store them. Remove and store detachable plugs from equipment that has them.
  6. Blow out lines. Use a high-powered vacuum to blow the water out of the plumbing lines. Then insert plugs.
  7. Cover the pool. Apply your winter pool cover and secure it in place with clips. If you want the best protection and ease of application, consider having the pros install an automatic, retractable pool cover instead.

Don’t think you want to tackle all of those steps on your own? Great news: You don’t have to!

At Royal Pool & Spa, we specialize in comprehensive swimming pool closing and opening services and can handle the entire winterization process for you. We’ve been closing Twin Cities pools since 1988 and will ensure your pool is properly shut down and ready to withstand the cold.

Schedule Swimming Pool Closing With Royal Pool & Spa

When it’s time to close up your Minnesota pool for the winter, let our team at Royal Pool & Spa help you out! We’ll ensure your pool is properly closed so it’s able to withstand sub-freezing temperatures without suffering damage. Proper pool winterization is imperative to ensure long-lasting performance, so if you’re unsure how to close your pool, calling in the pros is in your best interest.

To schedule a pool closing, feel free to give us a call today at 651-779-7606 or contact us online, and we’ll get in touch promptly.