Winter & Off-Season Pool Care

Maintain a Clean and Secure Covering

Maintaining a proper covering when your pool is closed is not a one-time thing; you must ensure that the pool remains fully covered and that the cover itself is undamaged, securely attached, and reasonably free of debris. Heavy debris such as wet leaves can weigh down the cover, causing a puddle of dirty standing water to form which can be a breeding ground for bacteria and may leak into the pool. A leaf net can help with this. Any frozen brush or trees around the pool can damage the cover as well, so be sure to trim nearby branches back.

Prevent Algae and Microorganism Growth

When your pool is closed, algae and other organisms can flourish in the dank environment under the cover. Nobody wants to open their pool in the spring only to find green scummy water, so it’s important to use an algaecide (which kills algae) or algestat (which prevents its growth) along with chlorine when closing your pool. Although these should keep your pool microorganism-free for about three months, it might be worth it to add another dose of algaecide mid-winter if you are in a warmer climate. Another batch of liquid chlorine should be added around a month before opening, or as soon as the water thaws if it was frozen.

Prevent Your System from Freezing

It is vital to check your circulation system throughout the off-season, especially if you are in a cold climate. Water expands when it freezes, and any water left over in your system can potentially cause damage to the pipes and moving parts which will be costly to repair. Depending on where you live, you may also want to drain the pool level to around 4-6 inches below the skimmer and make sure that the plumbing has been properly drained and winterized.

Close the Pool Late and Open Early

You may be closing your pool too early and opening it a bit later than is actually necessary. One lesser-known professional tip is to close the pool late and open it early, as minimizing the amount of time your pool is covered will reduce the chances of microorganism growth and other problems that can arise during the off-season. It is especially important to open the pool before the weather gets too warm, as bacteria and fungi thrive in dark, warm, and wet environments.

Experts recommend keeping the pool open as late as you can while keeping it clean and pH-balanced, even if it’s not in use, before closing it. You can shut off the heater and minimize pump usage using a timer in order to keep costs down. Open it in the early spring after the water has thawed rather than waiting until late spring when you will be more likely to see algae and bacteria buildup.