It happened.

The first leaf of Autumn fell—drifted—wafted—and landed—Right. In. Your. Pool.

Just a little leaf. But with him he brought tidings of cold, damp, gray months, and a seasonal reminder that your pool isn’t going to close itself.

For those pool owners who have a service that handles weekly or seasonal maintenance on their pool, closing is as simple as picking up the phone and scheduling a crew to come over—usually between Labor Day and Thanksgiving—and work their magic.

For others who want to do it themselves, winterizing their pool is a little more involved. Whether this is your first winter closing a pool, or you are just looking for a quick refresher on the when, why, and how, you’ve come to the right place.

When to winterize your pool?

The short answer is—whenever you want, as long as it’s done before temperatures reach freezing. Sure, your whole pool won’t freeze over during the first early snaps. But any water sitting in your filtration and heating system might, which will very likely cause damage to your pump, filter, heater… you get the idea.

Why winterize your pool?

You want to lengthen the life of your pool by taking proper care, and as mentioned above, that includes keeping water from freezing inside your system. If you live in the south where snow seldom flurries, you likely do not need to close your pool at all. But for those of us who live further north, closing is necessary both for the health of your pool, and the safety of people and animals who we do not want falling in and becoming popsicles.

How to winterize your pool?

This is a little less up to you, and a little more up to your pool. Different pools require different attentions.

But let’s break it down into (about) 6 easy steps.

First, is your pool free of all those non-essential items? We’re talking floats and toys, ladders, that random sneaker that appeared after that one party and no one has fished it out yet because it’s a conversation starter. Haul all that out and store it in a safe out-of-the-way place like a shed, garage, or bin where it can’t be damaged by the elements or whiskered minions of Mother Nature (you don’t want mice chewing through your pool noodles and building nests in your water polo net!)

Second, is your pool free of all the leaves and twigs that are floating on the surface of the water? Scoop those nasties right out of there! If you have a vacuum system or even a robotic cleaner, run this also to clean up any natural debris (leaves, dirt, bugs, etc.) that may have settled on the bottom of your pool. It may seem like a waste of time to clean your pool so thoroughly for it to go unused for the next few months. But I promise, you do not want that stuff sitting in your pool, breaking down and festering all winter, decomposing, staining, and all in all turning your pleasant, swimmable pool into the swamp where Shrek makes his dwelling. The goal of a good winter closing process is to make your spring opening as painless as possible.

Third, once all that visible debris is cleaned out of the pool, brush your walls, floor, stairs, and benches, and add a sanitizing shock and other winterizing chemicals to the water. At Denscot we use liquid shock, an algaecide, and something called Spring and Fall Pool Magic to help control organic contamination when we close our pools. This helps us clean out whatever is left in pools at the end of the season and sets us up for an easy breezy opening at the start of the next season.

I'd like to note here, that your regular chemicals (pH, Calcium, Alkalinity) should be balanced before you add in your winterizing chemicals. And if you’re closing the pool yourself, once you’ve added these chemicals, go ahead and run your filtration system for a few hours before proceeding. 

Fourth, you’re going to drain the water to just below the skimmers.

Step four-and-a-half: Stick with me here. Take the drain plugs out of your filters and pumps and put them in a safe place where you will remember to find them in the spring. Then, remove all the water from your pump, heater and filter. Anywhere water typically passes through, make sure there’s no water left. At this point, you can borrow or invest in your own pool line blower and blow out the pipes to get all that water out of your system and plumbing lines. Typically, at this point is when we would add a plastic threaded tube called a Gizmo to the connection in your skimmer to block that entry point off for the winter. We’re counting on snow melting into your pool over the winter, and that is going to raise your water levels again. So even though you’ve drained the water below the skimmer level in October, there’s no guarantee that the water levels won’t rise high enough to get into the skimmer by March. Hence the Gizmo or other kind of plug in that skimmer.

Fifth, once all your plumbing lines are blown empty, plug everything. There’s threaded plugs and rubber plugs (also called expansion plugs) and duck plugs—and you can use any and every combo of all or one of these. It boils down to what works best for you and your pool. However, when it comes to plugging the pool lines, having professional input doesn’t hurt, just to make sure nothing gets missed.

Sixth, and final step: haul out that winter cover and put that pool to bed!

If it’s an inground pool, you will likely have deck or lawn anchors already installed at or close to five-foot intervals around the pool. Line up your straps to these anchors, and secure them using the springs that came with the cover.

If yours is an above ground pool, you get a few more fun trinkets! In addition to your cover, you should have an air pillow. These get inflated and placed on the surface of your pool water, with the pool cover draped over. Then fill bags or jugs with sand, and hang them from the edge the cover on the outside of the pool to weigh down the cover. If your pool is above ground, but has a deck built up around it, you can use water bags—typically a foot or so wide, and about eight feet long. Fill as many water bags as you need with water. Then drape the pool cover across the pool over the air pillow, and up onto the deck. Then place the water bag(s) on the edge of the tarp that is on the deck. This will help keep the cover secure and prevent it from falling back into the pool.

And that's it! My last-minute reminders are to take your time and pay careful attention to cleaning your salt cell or filter cartridge, making sure your heater lines are completely free of water, and turning off any electrical components. If you have any questions about what supplies you may need, or how to carry out any of the steps we’ve covered today, call your local pool service company, and they will be able to point you in the right direction.