Opening and Closing Your Pool: A Seasonal Checklist
In many parts of the country, pools have a swimming season and an off-season. How you close the pool in the fall largely determines how pleasant your spring opening will be. In warmer climates, many owners keep pools running year-round, but these same principles apply to any period of reduced use. This checklist covers the main steps and the reasons behind them.
Closing: start with clean, balanced water
Begin closing about a week ahead. Clean the pool thoroughly: skim, brush, and vacuum. Leaves and debris left in the pool feed algae and stain surfaces over the winter. Then test and balance the water: pH, alkalinity, and calcium hardness within normal ranges. Balanced water protects surfaces during months of sitting.
A few days before covering, raise chlorine to a higher level and let it come back down toward normal. Many owners also use a winterizing product according to its label. The goal is to start the off-season with clean, sanitized water.
Closing: lower the water and protect plumbing
In climates where water freezes, the water in pipes and equipment must be removed or protected, because freezing water expands and can crack pipes, pump housings, and filters. Typically, the water level is lowered below the skimmer and return lines, according to your pool type and cover instructions. Lines are then blown out with air and plugged, or filled with pool-specific antifreeze, never automotive antifreeze.
Drain the pump, filter, heater, and chlorinator by removing their drain plugs. Store the plugs in the pump basket so you can find them in spring. Remove and store cartridges after cleaning them. Some owners store small pumps indoors.
If your area rarely freezes, you may keep the system running on a reduced schedule instead. Some equipment includes freeze protection that runs the pump when temperatures drop.
Closing: cover securely
A well-fitted cover keeps debris out and, for safety covers, helps prevent accidents. Make sure the cover is properly secured with no gaps. For water bag covers, check bags regularly. Remove standing water from the top of solid covers during the winter so it does not stretch the cover or create a drowning hazard.
During the off-season
Check the pool occasionally. Look at the water level and cover condition. In mild climates where the water is warm, algae can still grow, so test and add chlorine as needed.
Opening: remove and clean the cover
When the swimming season approaches, remove the cover carefully to avoid dumping debris into the water. Clean and dry it before storage, so it does not mildew.
Opening: reconnect the equipment
Reinstall drain plugs, remove winter plugs from lines, reinstall cartridges and gauges, and reconnect anything removed. Inspect O-rings and replace dry or cracked ones. Raise the water to the middle of the skimmer opening. Prime the pump and start the system, watching closely for leaks and checking the pressure gauge.
Opening: clean and test
Skim and remove debris, brush walls and floor, and vacuum. Then test the water completely: free chlorine, pH, alkalinity, calcium hardness, and stabilizer. Adjust balance first, then raise chlorine. Run the filter continuously until the water is clear. A pool that was closed carefully usually clears within a few days. If the water is green, follow a full green-pool recovery plan.
Opening: safety check
Before anyone swims, check that ladders and handrails are secure, that the gate and fence latch properly, and that safety equipment is in place. Inspect lights and their cords for damage, and make sure the electrical bonding and GFCI protection are working; have a qualified electrician address any concerns. Remove anything that could allow children to climb over the fence.
Keep a seasonal log
Write down your closing date, chemistry readings, and any repairs needed. In the spring, you will know exactly what was done. Over time, the log becomes a valuable record of how your pool behaves and what it needs.
Doing it yourself saves money
Opening and closing a pool are among the most common jobs homeowners pay for. With a checklist, a test kit, and a few hours, most owners can do it themselves, and learn their own equipment better in the process.