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winterizing swimming pool with pool cover

Winterizing a Swimming Pool: The Proper Chemical Balance

Your family had a great swimming season and created some wonderful memories together. However, fall is now here, the pool toys are put away, and it’s time to start winterizing your swimming pool.

An important (and sometimes overlooked) part of preparing your pool for the colder months is to specially balance your pool chemicals while the pool sits idle. That’s right – even though no one is swimming in the water over the colder months, it’s important to take a few special steps just before closing to protect your pool through the winter.

The good news is that you don’t need any special winterizing chemicals to properly winterize a pool. You just need to make a few easy adjustments to your water balancing with chemicals you’re already using. By following the steps below, you’ll be protecting your pool from damage, and your pocketbook from excessive drainage.

Increase pH and Alkalinity in Your Pool

During the summer months, we traditionally keep a pool’s pH level at around 7.4 – 7.6. When winterizing a swimming pool, we recommend raising the pH to a range of 7.6 – 7.8.

We raise the pH level because in stagnant water, pH will naturally lower itself over extended periods of time, such as when your pool is closed. Low pH levels can damage your pool surfaces or your liner, resulting in staining, and have other negative effects on your pool. By bringing the pH level to higher than normal levels, we offset the natural pH decrease that happens over the winter. If we keep our pH at 7.6 when we close the pool, the pH level would dip well below the minimum threshold of 7.4 within a month or two…with five months still to go before opening again.

Next, we need to adjust the alkalinity level. During the summer months, the optimum alkalinity range is between 120 – 140 ppm. This range is adequate because we are constantly monitoring our pool’s alkalinity and adding the appropriate chemicals as necessary.

However, during the winter, we want to increase alkalinity so it’s in the 150 – 175 ppm range. These levels are raised because much like pH, alkalinity levels have a natural tendency to drop in stagnant water over long periods of time.

What can happen in pools where the water has a low alkalinity level? Liners can wrinkle or fade prematurely, or there can be negative effects on plastics that happen to be below the winter water level. Raising the alkalinity at pool closing offsets the natural decrease that happens over time, and keeps us within our threshold over the winter months. 

For Concrete Swimming Pools

When you start winterizing a concrete swimming pool, you not only need to adjust the pH and alkalinity levels as described above, but it’s important to also be mindful of your pool’s calcium hardness level. We recommend a calcium level above 200 ppm.

We increase the calcium level because your concrete pool relies on it to prevent erosion and weakening of your pool’s coating and of the concrete itself.

Calcium is a physical part of water chemistry so it will not fluctuate over time, even after their preliminary water tests during the summer (which is why many pool owners forget to monitor it during the swimming season). However, by ensuring it’s at an adequate level when you close your pool, you’ll be doing a lot to prevent any unwelcome surprises in the spring that can lead to expensive repairs. 

Prepare for Winter Before Pool Closing

The timing of properly balancing your pool chemicals for the winter is just as important as the chemicals themselves. We recommend that you making the adjustments before closing your pool for the winter. Here are some simple reasons why:

  1. Can’t make changes once the pool is closed: Once you close your pool and head indoors for the winter, you won’t be able to make adjustments again until the spring. After all, the pool cover is on, there’s no circulation to evenly distribute the chemicals, and the outdoor temperature is low. This makes it almost impossible to properly correct unbalanced pool chemicals after closing. It’s better to put the work in now and prevent worry and potential problems down the road.
  2. Prevents damage: Water chemistry has the potential to damage your pool over the course of the swimming season, which lasts about five months. This means that your pool is closed for the remaining seven months of the year, so the potential for damage is even higher.
  3. Stops staining: Your pool water will be sitting without chlorine for several months, taking away your best line of defense from organic and inorganic stains that result from debris that may settle on the bottom, or from foreign debris entering the pool over the winter. Keeping the pH and other chemicals properly balanced helps to stop these stains from occurring.
  4. Prevents worry: By taking care of the pool chemicals at the right time, you have peace of mind that your pool will be in good order in the spring, instead of spending a long winter worrying. 

Protect Your Investment Before Problems Start

You’ve invested a lot of money in your pool, and your family has come to rely on it as an important source of summertime fun. If you have any questions about how to protect your pool, even when you’re not using it over the winter, talk to the award-winning experts at Lakeshore Pools & Hot Tubs. Our goal is to help you have a great pool experience – even when you’re not using it.

Even better – call us to winterize your pool for you. We’ll make sure that everything is taken care of, including the chemicals! 

Swimming Pool Services in Etobicoke, Port Credit and Mississauga

When it comes to winterizing a swimming pool, we’ve got you covered! Since 2004, the award-winning pool experts at Lakeshore Pools & Hot Tubs have been helping pool owners in the Mississauga, Oakville, and the Western Greater Toronto Area keep their pools in top shape – in both the on and off seasons. We promise to treat your pool like it’s our very own. Call us today at (905)-891-8818 or visit our store at 309 Lakeshore Road East in Mississauga to learn more!

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