Blog Header Image

Shock In The Winter?

To shock, or not to shock the pool during the winter months? That is the question...

Myth: If I shock my pool during the winter months, my pool won’t turn green.

Reality: The debate is still ongoing among pool professionals. Shocking the pool during the winter months can certainly help to avoid a green swamp-like pool in the spring. It's often recommended. However, poor water balance or improper application can lead to unintended consequences, such as discoloration and damage to pool surfaces.

Whether you decide to use pool shock or not, it's still important to test and monitor the water chemistry of a covered, winterized pool during the off-season. Do this at least twice a month when the water in your pool is not frozen.

Winter Pool Shock Tips

Leslie's Chlor Brite chlorine pool shock

If your pool has a solid cover over it, there will be less maintenance required. This is because sunlight and debris are blocked from entering the pool. However, if you have a mesh cover, then sunlight will certainly pass through, along with snow melt, rainwater, and some of the of the finer dirt, debris, leaf particles, and other things that land on your pool. These are things that can contribute to green water if sanitizer levels are absent or inadequate.

In our opinion, it's as the saying goes – it's better to be proactive than reactive. Check sanitizer levels whenever you test the water. Also visually inspect the pool to make sure the water isn't changing color. If sanitizer levels look good, and the water looks normal, you may not need to worry about adding shock. However, if there's little or no Free Available Chlorine remaining, and/or the water is taking on a cloudy haze or a green hue, add a dose of chlorine pool shock to keep the algae under control.

BONUS TIP: Before you add pool shock, make sure the water is properly balanced. Pay particularly close attention to pH and Total Alkalinity levels.

When adding pool shock during the winter months, it's important to make sure the water is well circulated. This can be tricky without the help of pool equipment.

leslie's fresh 'n clear non-chlorine shock

Start by pulling the cover back so that at least half of the pool is exposed. Pre-dissolve your pool shock (always follow label instructions), add it to the water, then vigorously brush the pool to agitate the water. Alternatively, you can also use a submersible pump and a length of hose to get the water moving. This step will distribute the shock more evenly throughout the pool, and it will prevent concentrated chlorine from damaging pool surfaces. For this reason, non-chlorine pool shock is a popular option in the winter. However, chlorine-free shock isn't as effective against algae outbreaks, and it can only be used if Total Available Chlorine levels are higher than 2.0 ppm.

An extra bit of prevention in the winter will make it so much easier to open your pool when the weather warms up again.

Need Help?

If you ever run into water chemistry issues during the off-season, bring a water sample to your local Leslie's for a free AccuBlue® water test. Or if you have any questions about maintaining or shocking your pool in the winter, just let us know! Our friendly pool experts are always here to help.

Facebook  Twitter  YouTube  Instagram