As a pool owner in Chicago's North Shore or Northwest suburbs, timing is everything — close too early and you lose swim days, close too late and you risk frozen pipes and cracked equipment; open too early and algae gets a head start, open too late and you're scrambling to get your pool ready once summer's already here. This guide covers how to time both ends of the season, plus the step-by-step process for closing your inground pool the right way.
When to Close Your Pool in Chicago
In Illinois, the best time to close your pool is between the second and final week of October, once daytime highs have settled into consistently cooler weather but before the first hard freeze puts your equipment at risk. Waiting too long into November raises the odds of freezing pipes, wind damage, and early snow — all things a proper winterization is meant to prevent. Once you've settled on your closing week, use it as your pool closing schedule and start prepping a week or two ahead so you're not rushing the process during a cold snap.
If your pool remains unclosed heading into winter, it's vulnerable to algae infestation, freezing pipes, wind and snow damage, and more — which is exactly why pool winterization is a non-negotiable part of inground pool maintenance in a climate like ours.
When to Open Your Pool in Chicago
Just as closing has its window, so does opening. As Chicago moves out of the last of its cold, unpredictable spring weather, it's time to start your pool opening schedule — pulling the cover, getting the water tested and balanced, and getting your equipment running again before the first warm weekend hits. Opening earlier rather than later gives you time to catch and fix any issues (a cracked line, a tripped breaker, cloudy water) before you actually want to swim, instead of finding them the day of a pool party. If you're not sure your pool made it through winter without any surprises, that head start matters even more.
Whether you handle your own Chicago seasonal pool care or have AAA Pool Service take care of your pool opening for you, the same principle applies to both ends of the season: plan ahead of the weather, not in reaction to it.
Closing Your Pool Step by Step
To make this process easier, we've compiled a list of steps required for you to successfully close your pool on your own.
Step #1: Check For Damage
The first thing you’ll want to do is check your pool for cracks, leaks or tears in the pool or the liner. These issues need to be addressed and repaired before you close the pool.
Hopefully, you won’t find anything, but if you do, you’ll need to assess the severity of the damage. Small tears can be easily replaced by your local pool professional without needing to replace the liner, but if there are several leaks or large tears, this is probably as good a time as any to replace your lining.
Replacing your lining requires your pool to be drained and can be done before closing or when you open the pool for the next season. Keep in mind, though, that postponing installation until the spring could lead to the foundation of your pool suffering damage during the winter.
Step #2: Test The Water
If you don’t carefully check your water before closing your pool for the winter, you could be left with an algae infestation when you open it again in the spring. Unfortunately, even closing your pool properly isn’t a 100% guarantee that you won’t face this problem.
To take preventative steps against this, check to make sure your pool is chemically balanced before closing. Use a standard chemical testing kit, and if anything is a bit off, add the chemicals the pool is low on to balance it out. You’ll want to be sure your pool is at the correct chemistry before closing it up to avoid corrosion, staining to the liner and scale build-up.
Step #3: Remove Everything From The Pool
When closing your pool, don’t forget to remove everything in or attached to your pool that might suffer in winter climates.
This includes:
- Diving boards
- Pool ladders or slides
- Pool toys
- Ropes, baskets or wall fittings
- Skimmer baskets
One note of caution – let everything dry completely before storing. You don't want to open your pool next season only to these items covered in mold or mildew.
Step #4: Add Antifreeze
To prevent your pipes from freezing, you need to backwash both the filter and heater to remove all the excess water in your pool's pipes. Leaving standing water will cause cracking and can most likely guarantee a hefty repair bill come spring.
If you have the right tools, including a Shop-Vac, you may be able to remove excess water after backwashing on your own.
Start by covering all of the exposed pipes with duct tape and removing the return jet fittings and drain plugs. After draining the water from the pump, filter, and heater, use the Shop-Vac to get any remaining water. Then force antifreeze through the empty lines, before finally sealing these openings up with a rubber plug to keep them dry.
This method, when combined with backwashing, will ensure you've removed 99% of the water from the pipes.
Step #5: Drain The Pool (But Not All The Way!)
You should never drain the pool completely — that will cause damage to your liner due to the cold winter temperatures. But you probably need to drain at least a little bit of water to prevent your tile from cracking.
The amount that needs to be drained will depend on the material of your pool. Once you know how much should be drained, you'll need to rent a sump pump and have a hydrostatic valve installed on your pool. With these two in place, you'll simply lower the water below the lowest pool return. This will protect your tile from cracking.
Step #6: Cover The Pool
It’s time for the final step – covering your pool!
To begin, you’ll want to consider if you should use a mesh or vinyl pool cover. There are pros and cons to both, but the main difference is that with a mesh cover you’ll likely have an algae infested pool when you open, necessitating a cleaning as soon as you open, while with a vinyl cover you’ll have to run a submersible pump during the offseason.
Once you’re ready to cover the pool, check your cover for rips or tears. If there are any, patch them with duct tape to prevent debris and animals from entering the pool during the winter. Your final step is to secure your cover tightly to your deck anchors.
You’re Done!
There you have it — a successfully closed pool, timed right for Chicago's seasons. A properly closed pool will save you money in the long run and ensure that, come next summer, you'll be able to fully enjoy your pool without any unnecessary headaches or delays.
If you don't have time to follow these steps or close your pool yourself, give AAA Pool Service a call! We'd be happy to take care of your pool closing needs — or get your pool opened and ready when the season turns back around — so you can rest easy all year long.
Frequently Asked Questions
When should I close my pool in Chicago? Between the second and final week of October, before the first hard freeze puts your pipes and equipment at risk.
When should I open my pool in Chicago? As soon as Chicago's spring weather turns consistently mild — opening early gives you time to fix any issues before you actually want to swim.
What happens if I don't close my inground pool properly? An improperly closed pool is vulnerable to algae infestation, freezing pipes, and wind or snow damage over the winter.
Does AAA Pool Service offer both pool opening and pool closing? Yes — AAA Pool Service provides both pool opening and pool closing services throughout Chicago's North Shore and Northwest suburbs.
