How Winter Affects Your Backyard Swimming Pool

Winter is undoubtedly the harshest season of the year here in Maryland and Virginia. If this is your first winter with a backyard swimming pool, you may be unfamiliar with how to make it to spring unscathed. Should you simply cover the pool and wait until warmer weather arrives? Maybe you should drain it entirely to avoid the risks of the freeze/thaw cycle.

Actually, neither of these solutions is correct. Closing your pool is a delicate process that requires an understanding of how winter affects in-ground swimming pools.

Can I Cover and Ignore My Pool All Winter?

You got the first part right—you should protect your pool with a high-quality cover. This saves time and money by maintaining a better chemical balance, reducing the risk of algae growth, and lowering pool heating costs. A safety pool cover also eliminates the risk of accidents or injuries around your pool while it’s not in use this winter.

However, merely covering the pool is not enough. If you ignore it all winter, you could leave the plumbing lines vulnerable to freezing. Plus, even though a cover reduces contamination issues, it doesn’t eliminate them altogether. If you aren’t vigilant, you’ll have a massive cleanup job on your hands come spring.

Should I Drain My Pool?

The short answer is no—you shouldn’t drain your in-ground swimming pool for the off-season. This would force you to start from scratch in the spring, paying high water costs to fill the pool and risking sanitation issues or algae blooms if you can’t get the chemical balance just right.

Draining a large in-ground swimming pool also presents the risk of heaving. This is when the shell pops out of the ground due to a rising water table level. Your pool is more at risk of heaving if you drain it because the shell weighs substantially less without any water in it.

So How Should I Close My Pool for the Winter?

Preparing your swimming pool for cold weather is relatively simple, but you may want help from a professional to ensure every step is performed correctly. Here’s what’s involved when closing your swimming pool for the season:

• Clean the water to remove as much debris as possible.
• Test the pH level and add winterizing chemicals as needed.
• Drain the water to just below the skimmer opening.
• Blow out the plumbing to remove water from the pipes and prevent freezing.
• Cover the pool to seal out debris, reduce evaporation, and trap heat inside.

Following the initial closing process, it’s wise to schedule two additional winter visits from a pool maintenance specialist. A technician will test and treat your water, adjust the cover, and check the system.

Millennium Pool Service would be happy to assist with all your pool closing needs! We have over 35 years of experience servicing pools in the DC metro area. For more information, or to schedule services, please contact us at 703.939.5062 in Virginia or 301.591.3750 in Maryland.