How to Winterize Any Type of Pool Filter—Fast

If only our calendars had a filter to catch all the months we’d rather be without. I’m sure I’m not the only one who would seriously consider getting rid of the freezing months of winter. But unfortunately, that kind of filter just doesn’t exist. And so every year, pool owners issue a collective sigh before switching out shorts for jeans and sandals for sneakers—and that sigh gets even louder when they realize it’s time to close up their pools for the season. The good news is that although there are a few steps to closing your pool for the winter, closing your pool’s filtration system couldn’t be more straightforward. I’ll explain what winterizing your pool filter entails, why and when you should winterize your filter, and how to winterize a sand filter, a D.E. filter, and a cartridge filter—and nail it on the first try. 

What It Means to Winterize a Pool Filter 

Unless you live in a tropical paradise and can swim all year long, you probably want to close your pool for the winter—after all, you’ll save a ton on your monthly energy bill without running your pump for eight hours or so a day. Plus, if you live in a place with freezing temperatures, not closing your pool or winterizing your pipes properly could lead to a pretty costly toll. Part of properly closing your pool involves closing your pool filtration system, which involves disconnecting it from power, cleaning it out, uninstalling it, and storing it away for the season.

Closing season is the perfect time to cut operating costs—especially if you get even better perfomance as a result. Try the 1.5 HP Variable Speed Blue Torrent Thunder In-Ground Swimming Pool Pump—it pays itself off in under a year, is eligible for rebates, and also comes with a lifetime warranty. As customer Eric D says, “Day one, I fired this pump up and it ran clean and fast.”

Why It’s Important to Winterize Your Pool Filter 

It’s only important to winterize your pool filter if you’re not going to be running your system for the winter. (If you are planning to swim all winter long and have the climate for it, you’re in the very lucky minority.) If you are closing your pool down for the season, it’s important to winterize your pool filter for a few fairly grave reasons:

1.     Costly Cracking

If you happen to live in a place that experiences freezing temperatures in the winter, not closing your pool filtration system properly could lead to your pipes cracking. Make sure to not just close down your filter for the season, but to also blow out your pool lines.

2.     Bad Bacteria

Let’s say you close down your pool filter by simply unplugging it. Sounds great, right? Well, not exactly. All the contaminants that your filter picks up will be left to fester in the perfect conditions—for months! Remember, your water passes through your filter before returning back to the pool. You’re not going to want a mess of gunk in your filter tank on pool opening day next spring.

3.     Extreme Exposure

Even if your filter itself doesn’t crack, leaving it outdoors for the winter could cause premature wear and tear. Chances are that if you’ve already picked out the right filter for you, you know they don’t come cheap. Make sure you take care of yours by winterizing it properly and storing it away in a safe, dry place.

how to winterize any type of pool filter

When to Winterize a Pool Filter 

When it comes to the right pool closing routine, a few steps that make use of a working filter have got to be checked off the list before you close it down for the season. Make sure you winterize your filter at the proper time, whether you’re closing an above-ground pool for the winter or an inground model (here’s the routine for closing an inflatable/intex pool for the winter, too). This is usually after you’ve brushed your pool with a brush like the BLACK+DECKER 360 Degree Patented and Professional-Endorsed Pool Brush, vacuumed your pool with a powerful vacuum like the Blue Torrent MyBot In Ground Robotic Pool Cleaner, and achieved the perfect chemical balance for pool closing, including shocking your pool. You’ll also want to make sure you’ve drained your pool, if you need to. Got those off the list? You’re ready to go.

Closing season is the perfect time to plan for the future—and an efficient pump will save you tons of cash and effort to come. For above-ground pools, try the Copper Force Above Ground Pool Pump, which has a start capacitor and different horsepower options. According to customer Doug Paar, “The pump is very quiet and has good pressure. I would recommend.”

How to Winterize a Sand Filter—In Five Steps 

If you have one of these classic crowd-pleasers, you already know just how efficient they can be. Sand filters are designed to catch particles that are in the 20-100 micron range, but the sand media can be switched out for media like glass that can trap even smaller particles. And in either case, the more you use it, the more jagged and trapping the media gets—until the tank is so pressured that you need to switch it out entirely, which only happens every few years.

It would be a waste of time and money to switch out your sand every time you close your pool, so the goal here is to keep your filter pump, your hoses, and your filter media sorted out, safe for the winter, and ready to rev up next spring. Get ready to get to know your top mount valve, which can be located on the top of your sand filter pump.

1.     Begin With a Backwash

All that gunk that your sand filter has caught? You’re not going to want it sitting, festering, and potentially even growing during the winter—especially since your ideal storage place is an indoor, safe place that might just be the right temperature for bacteria to thrive. Give your filter a backwash to keep it fresh this season. After the water runs clear from the nozzle, you’re done backwashing. Power it down to start this next step. 

2.     Give It A Rinse

After you’ve finished your backwash, go ahead and move the valve to the “rinse” position and let it run for thirty seconds. This is another measure to keep bacteria from making a happy home of your pump.

3.     Wrench the Valve to Winterize

Now that your sand or other media is as clean as it could possibly be (without a total replacement, that is), it’s time to turn that valve to the “winterize” setting. This will allow water to drain from your valve.

4.     Disconnect the Drain Cap

The top mount valve of your filter pump is sorted out, but your filter tank still has a ton of water in it—and that’s not going to store well this season. You’ll want to completely drain all the water from your tank by unscrewing and removing the drain cap at its bottom. You’re not going to reattach that cap, so make sure to store it somewhere easy to find for next spring. While you’re at it, remove all your filter’s hoses as well.

5.     Store It Away

Remember, your winter cover is going to get some serious debris over the next few months—and left unattended under that weight, it could fall into your pool and bring all that gunk with it. Keep your cover light and secure with the heavy-duty Sunnora 1500 GPH Swimming Pool Submersible Pump. It comes with its own XL discharge hose to get water off your cover fast.

Remember, your winter cover is going to get some serious debris over the next few months—and left unattended under that weight, it could fall into your pool and bring all that gunk with it. Keep your cover light and secure with the heavy-duty Brute Force 1250 Pool Cover Pump. According to customer Eric Zimmerer, “Love it! Saves so much time.”

how to winterize any type of pool filter

How to Winterize a D.E. Filter—In Five Steps

A little more high-maintenance than other filters, the D.E. filter is used to trap particles that are down to 3-5 microns. That’s pretty tiny, considering a human hair is about 50 microns in diameter. If you’ve done your research on what type of pool filter is right for you, you know that D.E. filters also have some serious downsides—they are, after all, believed to be toxic and even carcinogenic. When winterizing your D.E. filter, you’re going to want to use as much caution as you do when you give your filter a normal backwash or administer any other type of care.

1.     Make Sure You’re Prepped

Everything in due time. Again, your filter should only be winterized after you’ve cleaned your pool, achieved the perfect chemical balance for pool closing, drained part of your pool if you need to, and powered off your pool pump. Once this is done, you’re ready to winterize your D.E. filter. 

2.     Bump that Bump Handle

If you have this type of filter, you should be well familiar with the bump handle. This lever is built into the cap of the filter pump and moves up and down. But don’t be fooled by the simplicity of this part: when using this handle, it’s all about technique. In this case, you’ll want to move the bump handle up and down about ten times. Go slow when pushing the lever downward, and go fast when pulling it upward.

3.     Already Feeling Drained?

The last thing you want is to leave a full tank of water and bacteria alone to fester for the winter. Drain out your filter pump by opening the shutoff valve or drain plug at the bottom of the tank. While the water drains, continue to move the bump handle. 

4.     Disconnect Those Connections 

To finish getting rid of the water in your filter tank and prepare it for storage, go ahead and detach all pool hoses, connections, the tank cover, and all bolts on the lid of the filter tank. Some D.E. pool filters will have one bolt and a clamp—if this sounds like yours, remove both. This will give you access to the inside of the filter tank.

5.     Rinse and Restore

We’re at the end of our winterizing process, so now it’s just time to finish the job. Give the inside of the filter tank bottom and the D.E. fingers or grids a rinse. Those grids are where the actual D.E. media sits, so be sure to take the necessary precautions. After thoroughly rinsing, reinstall all the parts of the filter you removed, including the tank cover and bolts, except for the hoses and connections. Store it away in a dry, safe place for the winter and you’re done.

The next part of closing your pool involves using a winter cover, which is at risk of collapsing under rain and debris this winter—but that can be prevented with a cover pump that works on its own. Keep your cover light and secure with the BLACK+DECKER 800 GPH Automatic Pool Cover Pump, which detects up to a quarter inch of rain and works fast.

How to Winterize a Cartridge Filter—In Five Steps 

Cartridge filters are like the smart cars of pool filtration systems. They work well for smaller pools, they’re environmentally-friendly, and they’re not exactly made of horsepower. Although they’re a little more expensive than your standard sand pool filter, they don’t require backwashing, their cartridges run cheap, they filter out particles that are as tiny as 10 microns, and they’re the easiest to winterize. You’ll zip through this process like a two-person seater in the carpool lane. 

1.     Power Off, Pump Prepped

At this point of your pool closing routine, your pool pump should be powered off and removed from its power source, so you have no unwelcome surprises thanks to automatic timers. Once that’s done, you can drain out all the water from your pump, and clean your strainer basket of leaves and debris. 

2.     Unhook Your Hoses 

Next, go ahead and disconnect the filter hoses that are attached to the pool. You’re just not going to need them anymore, and it’ll be good to get them ready to be put away for the winter. These hoses usually are secured with metal clamps that are easily removed with a flathead screwdriver.

3.     Open Sesame—After Some Relief

Unlike a sand filter, you’re going to need to open up your filter tank to get to your cartridge filter. Thankfully, a cartridge is cleaner to pull out than pounds and pounds of messy sand. But before opening it up, make sure to use the air relief valve to bleed all that extra pressurized air out. Then, pull out the cartridge. If it’s on its last legs, replace it with a reliable cartridge filter. If it’s still got some life, clean it according to the manufacterer’s instructions. Usually this will involve submerging it in a cleaning fluid. 

4.     Dry It Out

One of the biggest regret by pool owners is moisture that’s left undisturbed for months, so don’t just throw that newly cleaned filter in the tank, close it up, and store it away. Let it dry! And I mean really, really dry. Hold off on this next step until your cartridge filter and pump are dry as a bone. 

5.     Store It Away for the Winter

You’ve properly winterized your cartridge filter, so now it’s time to finish the job. Store the filter tank, the filter cartridge, and your hoses in a safe, dry, and preferably indoor place for the winter. Don’t forget that pool pump, too—but make sure it’s dry first. Once everything is moved, you can move on with the rest of your day. Spring will come soon enough, I promise!

Since we’re thinking of the future, remember that as of 2021, the switch to variable-speed pumps will virtually be federal law. Thankfully, the Blue Torrent 2 HP Variable-Speed Pump is ultra-powerful, comes with a lifetime warranty, eligible for rebates, and pays itself off in under a year by energy saved. As customer Bill Britton says, “Runs great. Super quiet.” 

how to winterize any type of pool filter

No Filter!

Now you’re going without a filter—and without swim days—but not for long. There’s no filtering out the cold months. But the warm months are just as inevitable. Besides, there is some merit to winter: it’s got some pretty great holidays and family time. And thanks to your hard work, your pool will be more than ready to rev up next spring. In the meantime, enjoy.


This article explains how you can backwash your pool filter efficiently. Want to know how to clean the bottom of your pool? Read more here.

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