How to Close Your Pool for the Winter
By Kimberlee Courtney
If you live in an area with a seasonal climate, the early fall typically marks the end of your swimming season, and you will soon need to close your pool for the winter. Properly winterizing your pool is essential for preserving the structure, equipment, and water over the next several months—and ensuring a pleasant, hassle-free opening come spring. Here are the key steps and important tips to follow when closing your pool for the winter.
1. Time it right. According to most industry experts, the best time to close your pool is when daytime temperatures begin to range in the low 70’s to 60’s and nighttime temperatures drop into the 40’s --typically mid-October. Once the water temperature is lower, chlorine demand is reduced, meaning it will last longer over the winter. If you close your pool too early, the winter protection chemicals will not last into early spring and you’ll risk the growth of algae. During the weeks your pool is open but no one is swimming, you can place a leaf net over the water’s surface to prevent leaves from falling into the pool.
2. 2. Do a visual inspection. Make sure the pool structure and all equipment are in good working order. According to the Association of Pool & Spa Professionals, any structural defects or broken/worn equipment should be fixed prior to closing your pool to prevent further damage and to avoid any issues during the opening process.
3. 3. Test chemical levels the week before closing. Approximately three to seven days before closing the pool, make sure the water is chemically balanced and adjust levels if necessary. Imbalanced water can corrode the pool surface and cause scale to build up. Chemical levels should be as follows:
pH: 7.2 – 7.6
Alkalinity: 80 – 120 ppm
Calcium Hardness: 175 – 250 ppm
Chlorine: 1 – 3 ppm
Unfamiliar with these terms? View our Water Care Glossary
4. 4. Add winterizing chemicals. Be sure to follow manufacturer’s instructions, but the general procedure for adding winterizing chemicals is as follows: Mix any granular winterizing chemicals in a bucket to make sure they are totally dissolved before adding them to the pool. Undissolved granules can settle on the pool floor and stain the liner. Allow the chemicals to circulate in the pool for even dispersal.
5. 5. Drain the water to recommended level. Drain water from the pump and drop the water level down 12 to 18 inches below the skimmer opening or just below the return lines. This will allow any water in the plumbing lines to drain back into the pool which will prevent water from freezing in the pipes and causing damage. Once all the water is removed, plug the jet and skimmer holes to prevent water from getting back into the lines.
6. 6. Shut off equipment and timers. With the water level below the jets, the pump can be damaged if it runs without proper water flow. It’s important to make sure any timers are disabled so that the pump does not accidentally turn on.
7. 7. Put on the pool cover and secure it. Winter swimming pool covers come in a number of different types, so it’s important to follow the manufacturer’s instructions to ensure proper installation. Check that edges are tightly sealed to prevent wind from getting under the cover and allowing debris and leaves to enter the pool.
8. 8. Store chemicals properly. Keep pool products in a cool, dry, well-ventilated area separate from other products such as paint, fertilizers, gasoline, and any flammable materials. Make sure products are tightly sealed in their original containers and placed in an area that is inaccessible to children and pets. Liquid products such as algaecide, liquid chlorine, and liquid testing agents can be disposed of since they typically expire by the next pool season and will need to be replaced. Note: Most unused pool chemicals must be disposed as hazardous waste. Contact the product’s manufacturer or your local hazardous materials group to learn the proper disposal procedures of unused pool chemicals.
9. 9. Prevent access to the pool. Install locks on all doors and gates leading to the pool area and invest in a safety pool cover. A swimming pool is less likely to be supervised during the winter months, so it’s important to have several layers of protection in place to keep children and pets safe.
10. 10. Practice off-season care. Continue to check on the pool over the winter. Rain and snow can raise the water level in the pool and put too much pressure on the cover. Use a pool cover pump to drain off excess water so that the cover does not stretch out or sink. Also remove any heavy debris or fallen twigs that could damage the cover. Do a couple quick inspections to make sure the winterizing chemicals are working. It may be necessary to add a couple gallons of liquid shock mid-winter and/or check on the pool water in early spring.
Photo courtesy of Meyco Products, Inc.