A popular debate among pool owners is whether to use a winter swimming pool cover or not. Some folks swear by it, while others think it’s unnecessary, and even unsightly. But does covering your pool make that much of a difference? Are you putting your pool at risk if you don’t cover it?
Those are valid questions, ones that often leave pool owners scratching their heads, and concerned that they’re not doing what’s best for their pool. That’s why we’re here — to discuss the best practices for your pool and if you truly need a winter pool cover.
Do You Have to Use a Winter Swimming Pool Cover?
In short, no you don’t. Your pool won’t be damaged beyond repair or needing a major cleanup if you choose to go without a winter cover. But winter swimming pool covers protect your pool against an array of problems that you likely don’t want to deal with come pool opening season.
Stains, scaling, algae growth, and imbalanced water chemistry are just a few dilemmas that can arise if you don’t use a winter pool cover. Pool covers block both debris and sunlight from entering your pool — conserving winter chemicals and protecting the pool’s structure.
We recommend using a winter pool cover to provide your pool with the best protection possible over the chill months. However, if you decide to keep your winterized pool uncovered for whatever reason, follow the steps below to guarantee a clean, healthy pool when it’s time to reopen it.
Keep the Pool Clean
With the pumps and pipes winterized, you can’t vacuum the pool through the system. But that doesn’t mean you can’t keep your pool clean! Use a leaf rake to skim your pool and remove any leaves, bugs, and other debris from the water. Grab a pool brush to scrub the walls and floor of your pool and circulate the water.
Test and Balance the Water
Use a test kit or strips to check the pool water once a week. Rain and snow will enter your pool without a winter swimming pool cover, damaging the water and chemicals, like pH, Total Alkalinity and Calcium Hardness. In addition, be sure that your Cyanuric Acid level is up to 50 ppm, to protect your chlorine from the sun. To add chemicals to an uncovered pool during winter, pre-dissolve by adding to a bucket filled with water, then pour the solution around the edge. Brush the pool well afterwards, to help dissolve and disperse the adjustment chemical.
Use Chlorine and Algaecide 
Keep your chlorine level up in the pool by filling a chlorine floater (or two), with tablets, and floating them in the pool with the baffles fully closed. Refill the floaters every few months, and test the water regularly to maintain 1 ppm of chlorine. For winter algaecide, add an initial dose of 1 qt per 10000 gallons, and a weekly maintenance dose of a good winter pool algaecide, like Algaecide 60 Plus. If you notice algae growing in early fall or late spring, shock the pool with a heavy dose of your favorite pool shock, and brush well. When the pool is frozen solid, or has water temperatures in the 40’s – you won’t need much chlorine or algaecide.
Open the Pool Early
When the water temperature rises, and sunny days grow longer, it can be hard to control algae growth without a pool cover. So plan on opening the pool about a month before normal, or when the water temperature rises into the 60’s. While the water is still below 65°F, you can run the pool pump less, 4–6 hours per day, to maintain clear water.
A winter swimming pool cover is an important piece of winter pool equipment, but not a necessary one. If you elect to go without one, keep your pool clean and healthy by following the steps above. A clean, closed winter pool means a clean, open summer pool!
We have a tree that has grown since our pool was installed 20 years ago, Should we wait until the leaves are off the tree before we winterize and cover our pool? Or should we winterize it now since we aren’t using it? We had an issue in the past with the leaves that had collected on the cover falling into the pool when we were taking it off.
Hi, sounds like personal preference, do you want to clean the leaves out of the pool, or off of the cover? We do have a product called a Leaf Catcher, a leaf net cover that lays on top of your winter cover. Once the leaves have fallen, one person can easily fold up the leaf catcher, and pull off all the leaves, in one motion.
We live in north central Arkansas. If we choose not to use a pool cover during the off-season what do you we need to do the maintain the pool while not in use? From the information I’ve read in your answers to other it seems we should continue on with our summer maintenance routines.
Hi Tim, you will do the same thing, just less of it ~ less filtering, less chlorine because the water is colder. Cleaning depends on your tolerance, but after the leaves have all fallen, maintenance will also drop. Be sure to run the pump if temps are below freezing, unless you are going to winterize the pool.
Hi Davy,
We live in Ohio and have an above ground oval pool. Our liner has a hole, so a new liner will be installed in the spring. Instead of buying a winter cover, we are considering not covering the pool for the winter. Someone said the cover not only helps with debris, but protects the pool walls from the winter winds that could potentially make pool unstable. Is that true?
HI Vicki, I guess the cover could deflect the wind somewhat, but that’s not a big deal, summer winds are pretty strong too! Go ahead and not cover the pool, always an option when the pool is going to be drained in the spring.
I usually have an issue with pool water coming through the cover when pumping off rain water. Then I have to get it filled in the Spring. What cover will keep that from happening as much, if there us one?
The better covers, mid-range to top-shelf, will have a tighter weave, and prevent water from oozing thru, and being pumped out with your cover pump. Or, look at the Ultimate 3000 cover which lets water into the pool thru a mesh strip across the center. Water does need to be lowered inside the pool, unless a return hose is left connected to drain the water continuously.
I have an inground pool in central California. I have a leaf net that I’m going to put on the pool for winter again. How often do I need to brush my pool during winter. Thank you for your help.
Hi Carol, if you are running the filter each day, perhaps every two weeks? I’d start with that and see how it goes…
I wonder if you can help please, we need to leave our pool due to Covid, so we are about to put into hibernation. We are worried as the daytime temperatures are still in the 30’s Celsius. Any advice is appreciated.
Hi Charlotte, the best thing may be to cover the pool, but continue to filter the water and maintain water chemistry. OR… cover it now with a winter chemical kit, and then just drain, scrub clean and refill the pool next season.
Good Morning. Due to extreme circumstances we didn’t cover our pool this winter. We always cover it and open it in the summer. The pool is more green than ever due to not being covered. We have used 16 bags of shock as we usually use about 12 to open it. When I backwash the filter I’m still getting clear water instead of green. Am I doing something wrong or did I destroy the pool by leaving it open all winter? We have been taking out all of the leaves we can get for 2 days now. I don’t know if I need more chemicals or if it’s time to empty the pool and start all over again? Any advice would be greatly appreciated.
Janet, it would be better if you can drain the pool, clean the pool and refill. Unless you have a very effective filter system, it may never clear completely. YOu can rent a pump at a rental shop to drain the pool. If plaster, drain it all the way and acid wash the pool. If vinyl or fiberglass, drain it only to within 3 inches of the shallow end floor, then refill.
Hi Davy,
We have a small (12ft diameter, 4ft deep) circular pool in the ground that we only use for 2 to 3 months in summer. For the rest of the year I would like to drain half the water out and put a ground level trampolin over the top. This would also act as a safety cover (the pool is otherwise left uncovered during the winter). I live in Austria and the pool normally freezes for several weeks in winter. What is the risk of the vinyl lining of the pool that is no longer covered by water becoming damaged?
Many thanks
Giles
Vinyl is best left covered during winter (or summer), however I’m not sure what would be worse, exposure to very cold air, or being in contact with a very cold sheet of ice, forming in the top 6-12″ of pool water? I see no problem with your plan!
I have an above ground pool. I usually empty it every fall and store it, however this winter I kept it up (uncovered). The water is green and slimy. Do I have to empty it and refill it with clean water or can I put chemicals in the water and use it? Would it be safe?
Hi Rachel, yes that’s the normal thing to do, balance the water (pH, alkalinity, calcium) and then shock the pool with a double or triple dose of granular chlorine shock. Brush the pool thoroughly and run the filter non-stop until clear. If you can see the bottom of the pool (floor), then you can usually bring it back with chemicals and filtering, is my general rule of thumb. If the water is green/black with very poor visibility, it can be better, cheaper/easier to drain and replace at least half of the water.
Can we pump off the winter cover pool water into the pool. We have a screened basket that would catch the leaves but most of the water sitting on the cover is clear.
Hi, you could if you need to. There likely is a lot of bacteria in the water on top of the cover, so give the pool a good shocking after filling and starting.
Question, actually. I run an apartment community and we do not cover the pool in winter. We are located in North Alabama where the temperature rarel gets under freezing, though it does from time-to-time. One of my maintenance team members thinks it’s OK to shut the pool pump off. I disagree and constantly ask him to turn it back on. Who’s right?
Hi Jane, well it depends on the temperature. You do want the pump running when freezing temperatures are expected or anything below 35° really, just to be safe. But, when temperatures are in the 40’s or 50’s, and no one is using the pool, you can reduce filtration to 6-8 hours per day (or less), and still maintain water quality. When water temps reach 65 deg. F, longer daily filtration is needed. If you run the pump less, you will save on wear/tear and on energy bills. The best route is a timer, attached to the pump, so that it will turn on/off each day, or several times per day. During the pool season, your county health dept may require that the pump be running during pool hours.
Hi Davy
What about at night during the summer ? Is it smart to cover my above ground pool every night ?
Thanks ! !
If you have a cover and want to preserve heat, covering the pool at night is a great way to go. Most people use a solar cover to retain heat, but a winter cover would also stop a lot of heat loss.