Unless you are lucky enough to live in a part of the US that stays warm enough to use your outdoor pool year round, you’ll probably need to take some steps to keep it clean and functional during the off season.
Preventing freezing in your pump and filtration system is of paramount importance—if water freezes in your pipes or equipment, it can cause cracks and other damage that will require costly repairs. The potential for freezing also makes it important to lower your pool’s water level several inches below your built-in skimmers or other cleaning/drainage system you have in place.
When not in use, during winter or any other latent period, your pool should be cleaned, covered and secured.
Many pool owners don’t realize that their pools remain chemically active even during the winter months; the water may be too cold for you to swim in, but there are certain algaes and other microorganisms that can thrive even in near freezing water. While you don’t need to actively monitor your pool’s chemistry during the winter of non-use, proper chemical dosing before you shut down your pool for the season can help you bring it back to life faster, cheaper, and with less of an environmental impact.
Proper Chemical Dosing to Winterize Your Pool
Before you cover your pool for the winter, whether or not you expect it to freeze, an extra dose of chlorine or a non-chlorine “shock” is often recommended. This will help eliminate any microorganisms that might have survived your standard chemical dosing regimen, preventing further growth and proliferation during the period your pool is not in use.
This extra chlorine or non-chlorine agent should be added at least 24 hours before you close up your pool and turn off its filtration system. Allowing your pool’s pump to circulate the water for a full day will ensure that all the water is treated effectively.
You should also check your pool’s pH level and add acids or alkalines as necessary to keep the Ph in the optimal range (between 7.4 and 7.6). This will make it easier to make your pool ready to use come springtime. Balancing Ph can take some time, and is something you’re ideally keeping up with throughout your pool’s use; if it’s been awhile since you checked and balanced your pool’s pH, be sure to start this process at least a week before you plan on winterizing.
After balancing your pool’s pH and giving it a shock treatment, your pool should be partially drained, all pipes and equipment cleared of any water, and your pool should be fully covered.
Bringing Your Pool Back to Life After a Winter Hibernation
When winter is over and you’re ready to use your pool again, don’t be surprised if the water appears murky or even green-tinted. You—or your pool technician—will likely need to add more chlorine as well as other standard pool chemicals and allow your pump to cycle them through. Repeated testing (or constant monitoring using an automated pool chemical testing system) and dosing over a period of a few days might be necessary to bring your pool back. After that, regular monitoring and maintenance will keep you enjoying the water until next winter rolls around.