With Labor Day behind us and cooler weather ahead, most pool owners around the country are beginning to think about winterizing their in-ground pools. Winterizing a pool keeps key components from freeze damage. It also saves a lot of time and money when spring rolls around and it’s time to re-open the pool.
One way to know, for sure, that it’s time to close the pool is when the nighttime temps are in the 40’s, and daytime temps are in the low 70’s. Closing the pool earlier that that causes algae overgrowth, but waiting till later might mean having to dredge fallen leaves out.
After you have determined it’s time to winterize the pool, it’s time to treat the water. Start testing the water during the course of a week to make sure that the pH is right. It should be in the 7.2-7.8 range to prevent scales, stains, and algae. When your water reaches this range, shock the water according to label instructions, and then run the pool filter for 24-48 hours.
After turning off the filter, shock the water according to the manufacturer’s instructions. Then, vacuum out the debris and add algaecide to the water. If you prefer, you can use a premade winterizing kit that includes all of the chemicals needed to properly close your pool.
Having shocked and vacuumed the pool, it’s time to remove everything but the water. Take out the toys, nets, ropes, hoses, ladder, and other decorative fittings. Remove the diving board and store it for winter.
With everything but clean water now gone, you can safely start to lower the water level. Opinions vary widely about just how much the pool should be drained, but it is true that some pool fare better with water left in as a buffer from the elements. When in doubt, follow the pool manufacturer’s advice on draining the pool. After closing the valve on the skimmer line, make sure to lower the water below the mouth of the skimmer, which could be damaged by freezing water.
With the pool water safely below the skimmer intake, it’s time to purge the water from the filter, hose, heater, and all other equipment. Remove and store any paraphernalia that can be removed. Follow the manufacturer’s directions about coverings and lubricants for the pool equipment.
Finally, install the pool cover. Make sure that the water bags are filled halfway to prevent gaps between the cover and the pool edge. It’s vitally important to keep out leaves, trash, and other contaminants after the pool cover has been installed.
For more information, consult the Association of Pool and Spa Professionals, and the National Sanitation Federation’s Joint Committee on Recreational Water Facilities.