What to do with my Pool in the Winter Months?

California residents usually do one of the following things with their pools during the winter:

• They winterize their pools by cleaning them, balancing the water chemistry, inspecting the equipment, covering them, and adding a freeze protector¹. This is done to protect the pools from freezing temperatures, save on maintenance costs, and preserve the pool condition for spring².
• They keep their pools open and running, but reduce the pump run time and the chlorine level. This is done to enjoy the pool year-round, especially if they have a pool heater or a solar cover.
• They drain their pools completely, which is not recommended because it can cause damage to the pool shell and the plumbing system due to the water pressure and the soil conditions in California³.

Here is a list of things to do in order to prepare in autumn to winterize a pool throughout the winter in California:

• Clean the pool and remove any dirt and debris you find in the skimmer baskets⁴.
• Remove all pool equipment and make sure everything is working properly.
• Check the pH and rebalance your pool water’s chemicals.
• Clean the filter to ensure it can function well during the cold weather.
• Cover the pool with a durable cover to prevent debris from entering and reduce water evaporation⁵.
• Consider adding a freeze protector to your pool system, which can sense a drop in temperature and activate the water circulation⁶.

Yes, there are some regulations regarding winterization of pools in California. According to the web search results, these regulations are mainly related to the following aspects:

• The enclosure or barrier that isolates the pool from the home and prevents unauthorized access. The enclosure must meet the requirements of the California Swimming Pool Safety Act, which specifies the height, material, openings, gates, and locks of the enclosure⁷.
• The safety pool cover that protects the pool from debris and reduces water evaporation. The cover must meet the performance standards of the American Society for Testing and Materials (ASTM), which specify the weight, strength, and durability of the cover.
• The suction outlets that conduct water to the recirculating pump. The outlets must be equipped with anti-entrapment devices or systems that comply with the ANSI/APSP performance standard, which prevent body or hair entrapment or evisceration⁸.

Yes, you need to shock your pool before winterizing it. Shocking your pool before you shut it down for the season will help prevent the growth of algae and other harmful bacteria⁹. We recommend shocking your pool two or three days before you plan to shut things down. That will give your pool water a few days to return to its normal chlorine levels before you proceed with the winterization process.

Shocking your pool means adding a large dose or “shock” of concentrated chlorine, either powder or liquid, to the water. It rapidly rebalances and adjusts chlorine levels in the water. Shocking raises the levels of “free” chlorine molecules that find and eliminate bacteria, algae, and other elements that can discolor or cloud the water or affect pool equipment performance¹⁰.

There are three main types of pool shocks: liquid chlorine, calcium hypochlorite (Cal-Hypo), and trichlor. Each type has its own advantages and disadvantages, such as pH, calcium levels, and dissolvability. You should choose the type that suits your pool needs and follow the package instructions for how to mix and apply the shock properly.

To shock your pool, you should first test your pool water to see what kind of shape it’s in. Test the pH, alkalinity, and calcium hardness and adjust them as needed. Then, add the pool shock to your pool water, either directly or by pre-dissolving it in a bucket of water. Make sure to wear protective gloves and goggles when handling pool shock. Run your pool pump for at least eight hours after shocking to circulate the water. Wait 24 hours before using your pool again.

Shocking your pool before winterizing it will ensure that your pool is properly sanitized and protected from the cold weather. It will also reduce the costs of de-winterizing your pool in spring.