Above Ground Pool Opening & Start-Up Tips

Spring has sprung! As the water temperature heats up, your above ground pool needs filtration and chemicals. If you already have an above ground pool in your backyard, we recommend opening the pool before the water temperature reaches 65°F. On the other hand, if you’re looking to purchase a new above ground pool, you’ll want to get it up and running right after installation. But how do you get an above ground pool ready for swimming?

Whether this is your first DIY pool opening or start-up, or whether you just want a refresher on how to open an above ground pool on your own, this post is for you! We’ll walk you through the 6 basic steps for getting pool water clean, clear, and sanitized for swimming. Let’s get started! If this is a new pool installation or a fresh start-up, you can skip ahead to step 2.

1. Remove the Pool Cover

The first step to open your above ground pool is removing the winter cover with care. If the water level is low, add some water under the cover to make sliding it off a breeze. Before you lift, use a leaf rake to scoop off any leaves, twigs, or debris—less mess now means less cleanup later. If you see water puddled on top of the cover, set a pool cover pump to work—standing water can weigh everything down and make removal tricky. A little prep here sets you up for a faster, smoother pool opening season.

Once the water is pumped off and debris is (gently) removed, release the cover cable and cover clips, which were used to secure the cover. With an assistant on the other side of the pool, fold the cover in half, then slowly and carefully pull it over the edge of the pool. 

Spread the cover out in the driveway or other large area for cleaning and drying. Avoid grassy areas, which can turn brown if covered for too long on a hot, sunny day. Once dry, fold the cover accordion style (fan fold) to make it easier to spread over the pool next fall. 

DIY TIP: Before folding and storing the winter pool cover, sprinkle both sides with talcum powder or Leslie's Alkalinity Up. This will help prevent mold and mildew growth while in storage.

Taking the extra step to treat your cover protects its finish, extends its life, and ensures it’s ready for action next season. Moreover, it helps avoid the frustration of opening your pool in spring only to find a musty, stained, or brittle cover. While this simple tip only takes a few minutes, it can save you money by maximizing the durability of your cover and keeping your above ground pool equipment in top shape. Protect your investment with this expert approach, and enjoy peace of mind knowing your pool gear is safeguarded until next year.

What If I Don't Have a Winter Cover?

If you're considering purchasing a winter cover for your pool, Leslie's has a wide selection in all shapes and sizes that fit any budget. These covers are designed for maximum protection against the elements, helping ensure your pool stays debris-free through the off-season. Quality materials mean better durability and a longer lifespan, so you won’t need to replace your cover as often.

Moreover, investing in the right winter cover now saves you time and money on spring clean-up and repairs, keeping your above ground pool in top condition year after year. With expert advice and premium options available, you’ll find the perfect fit for your pool and enjoy peace of mind knowing you’re protecting your investment the smart way.

2. Inspect Your Pool Equipment - Filtration System and Pool Plumbing

Next up in opening your pool: reconnect the filter system hoses to your above ground pool’s skimmer and return fittings, making sure each hose is firmly attached. Replace all drain plugs on both the pump and the filter, but skipping this step guarantees leaks later.

Install the return eyeball fittings, pop in the skimmer basket, and set your pool thermometer in place. Now’s also a good time to reattach your pool ladder or step system so swimmers have an easy way in.

Double-check for any winterizing plugs in the skimmer or return lines and pull them out. Each removed plug means smooth water flow ahead—and fewer headaches for you.

For threaded plastic plugs on the pump and filter, and for the filter pressure gauge, replace the old Teflon tape with new, wrapping three times in a clockwise direction for a tight seal. For plugs with a gasket or O-ring, apply Leslie's Pool and Spa Lube!

Also apply pool lube to the pump lid O-ring, and to any other sealing gaskets used in valves or unions. NEVER use a petroleum-based lubricant like Vaseline™ or WD-40™, as these will damage the soft rubber used in O-rings and gaskets. By using a high-quality pool-specific lubricant, you not only protect your equipment from premature wear but also ensure a watertight seal that keeps your system running smoothly. This simple step extends the life of your pump and filter, reducing the risk of leaks and minimizing costly repairs over time. It’s a premium preventative measure that helps you avoid headaches down the line, supporting both the longevity and efficiency of your above ground pool system. Moreover, properly lubricated seals will make future seasonal maintenance faster and easier, so you spend less time on upkeep and more time enjoying your pool.

Need a quick check that everything’s set up right? Bring in a water sample for a FREE professional grade 10-point test at your neighborhood Leslie's Retail Store. With industry leading AccuBlue Technology®, our pool experts will show you exactly what to do next—less guessing, more splashing.
Or, if you’d rather handle things poolside, test your water at home using a chemical test kit or Leslie's AccuBlue Home®. Using the same industry leading AccuBlue technology, AccuBlue Home generates accurate water testing results in about 60 seconds in the palm of your hand with the Leslie's Pool Care App.

3. Fill and Circulate the Pool

Once the filtration system is put back together, you can fill your above ground pool up to mid-skimmer level to continue the opening or start-up process. As the pool fills and the filter system is flooded with water, look for any water leaks in the filter hoses, valves, pump, and filter equipment. Take a slow walk around to look for any wet areas outside the pool, especially if this is a new install or if you found your pool water level very low under the winter cover.

Moreover, keeping a watchful eye during this stage is essential for protecting both your pool equipment and the integrity of your pool liner. While it might be tempting to rush the process, double-checking for leaks ensures long-term savings and better performance. Since even a small leak can cause water loss and damage components over time, early detection is a smart, value-forward move for both first-time and experienced pool owners alike.

My Pool Liner is Damaged. Where Can I Get a New One?

Leslie's offers a wide range of quality pool liners for most above ground pool shapes online. A new liner enhances appearance, protects your pool, resists wear and fading, and helps maintain water quality. With options tailored to fit your pool, you get long-lasting performance, easy installation, and fewer worries about leaks or costly repairs. Our experts are here to help you find the ideal liner for a reliable, hassle-free upgrade.

4. Start Up Your Pool System

Now comes the time to fire up the pump. First, check that all valves are open. For sand and DE filters, place the multiport valve into the “filter” position. Open the air bleeder on top of the filter to relieve air pressure, then flip the switch. It’s time to start up your above ground pool systems so you can finish opening the pool! 

Keep a close eye on the filter pressure gauge. If it should spike to 30 psi or more, shut down the system and re-check that all valves and wall returns are open and unplugged. Verify good water flow into the pool, and make note of the starting pressure on your clean pool filter. 

If the pump fails to start, check that the power supply is good and the GFCI outlet is not tripped. Next, check that the shaft and impeller spin freely. Often, a thin layer of rust can build up inside the motor, which can be broken up by manually turning the shaft back and forth.

DIY TIP: Having trouble with your above ground pool pump, filter, or pool cleaner? Just bring it to your local Leslie’s store. Our knowledgeable pool service technicians can quickly troubleshoot and repair the problem for free. The only thing you’ll pay for are the parts needed for the repair.

If you need to replace your equipment, Leslie's offers Pool Perks Loyalty Rewards for purchases. This means you can upgrade to energy-efficient pumps, high-performance filters, or any other premium pool equipment with less upfront cost, while also earning rewards points for every dollar spent. It’s a smart way to boost the longevity and efficiency of your pool system—without stretching your budget.

5. Clean the Pool

If this is a brand new pool with fresh water fill, you can skip this step for now. On the other hand, if this is an existing above ground pool you're re-opening, we can assume that you probably already know how to clean a pool. But did you know that the best order for cleaning is to skim the pool, then vacuum, then brush? It’s a much more efficient use of your time to clean the pool in this order. For large amounts of debris on the floor, use a leaf rake or a leaf bagger. 

While opening the pool, you may notice some staining on the vinyl liner. This is quite common after a long winter of stagnation — don’t worry about it for now. Many of these stains will disappear on their own once the water is balanced and chlorinated.  

It is important to remove debris from the pool before balancing the chemistry and shocking the pool, as heavy leaf debris and algae can negatively affect both.

If you're looking to upgrade your cleaning supplies, Leslie's carries the pool maintenance accessories you need for a clean and beautiful pool! Whether you want a durable leaf rake, an efficient pool vacuum, or a reliable pool brush for your liner, there's a premium option designed to make maintenance easier and protect your investment. These quality tools are crafted for long-lasting performance, saving you both time and effort while ensuring your pool stays inviting all season. Moreover, investing in the right accessories can reduce wear on your pool equipment and extend the life of your pool liner. Experienced pool owners know that having the right gear on hand means less work and more enjoyment, so choose cleaning solutions that match the convenience and longevity you value. With a wide range of options and expert guidance available in-store and online, Leslie’s makes it simple to elevate your cleaning routine for sparkling, hassle-free results.

6. Adjust Pool Chemistry

Before adding Leslie's Pool Shock to your above ground pool or using a Leslie’s Pool Opening Kit, it's important to test and adjust the water levels for pH, Total Alkalinity, Calcium Hardness, and Cyanuric Acid (chlorine stabilizer). Proper water balance protects your pool equipment, prevents damage to your vinyl liner, and ensures a safe swimming environment. Testing at this stage eliminates guesswork, so you can avoid costly issues and keep your pool protected from day one. If these critical levels are out of range, the effects can be more than cosmetic. Imbalanced water may cause corrosion, scale, or cloudy water, making routine care more challenging in the long run. Moreover, well-balanced water means pool chemicals work more effectively, saving you time, money, and hassle as you move into a season of clear, refreshing swimming. For more about water testing, please see our blog: Pool Water Testing 101.

Test your pool water with an at-home test kit that can give results for all four tests above. You can also bring a water sample to any Leslie’s store for a free 10-point AccuBlue® water test, which provides you with a precise water analysis and customized water treatment instructions to take home or review in the Leslie's Pool Care App. Or accurately test your water at home with the convenient AccuBlue Home digital pool water test device and membership.

After balancing the water, it’s time to shock the pool. Remember to keep the pump running on high speed when adding any chemical to the pool, and always refer to product label instructions for application and dosage instructions. Improper application can damage your above ground pool's vinyl liner. Therefore, always pre-dissolve granular pool shock in a clean bucket of water before slowly pouring it around the pool’s edge—this helps prevent bleaching or staining the liner.

Since the goal is to eliminate contaminants and ensure a safe swimming environment, don’t skip this essential step. Moreover, it’s wise to shock the pool in the evening or when the sun is low, as this prevents chlorine loss from UV exposure and helps maintain optimal sanitizer levels overnight. This smart approach not only contributes to water clarity but also extends the life of your pool liner and equipment, supporting consistent, safe enjoyment all season.

DIY TIP: Leslie’s Pool Opening Kits come with all the ingredients you’ll need to open your pool in the spring. All kits come with Chlor Brite Shock, Ultra Bright Advanced Clarifier, Pool Stain Remover, Algae Control, and more. Cut out the guesswork with our carefully pre-measured kits for pools up to 35,000 gallons in size.

Saltwater pool owners should also test for salt content, and may need to add a specific amount of pool salt to match the salt system manufacturer’s recommended saline level. For more information on pool water chemistry, shock, and water testing, check out our library of informational water treatment articles.

Next Steps After Opening Your Above Ground Pool

In the days immediately after opening the pool, the filter may need cleaning or backwashing, so keep a close eye on the pressure gauge. Once the pressure gets 10 psi higher than the clean pressure reading, it’s time to clean the filter. Also monitor the pool water level closely to ensure the pump stays primed and to rule out pool leaks. If the water was particularly dirty at opening time, your pool may need a few more cleanings before it’s ready for prime time use. But if you have balanced water chemistry, sanitizer levels in range, and clear water, there's no need to wait. Start swimming!

Simplify Pool Care with the Leslie's Pool Care App

To keep your pool in top shape throughout the summer, it’s important to keep up with proper water balance, regular cleaning and routine maintenance. The Leslie’s Pool Care App is your all-in-one solution for hassle-free pool maintenance. Whether you’re opening your pool for the season or keeping it sparkling clean year-round, this app puts expert tools and resources right at your fingertips. Download our app today!

To keep your pool in top shape throughout the summer, it’s important to keep up with proper water balance, regular cleaning and routine maintenance. Browse through our Expert Advice and Resource Center articles for tips and tricks on keeping your pool swim-ready. You can also check out our above ground pool maintenance checklist for more detailed instructions on above ground pools. 

Still have questions? Call or stop by your local Leslie’s to speak with one of our knowledgeable pool professionals. Don’t forget to bring along a water sample for a free AccuBlue® test, which precisely measures 10 different aspects of water chemistry in your pool.

Leslie's Resource Center

Other resources to help you stay on top of your routine maintenance, through our Expert Advice and Resource Center articles for tips and tricks on keeping your pool swim-ready. You can also check out our above ground pool maintenance checklist for more detailed instructions on above ground pools.
Our handy guides provide straightforward steps to help you prevent cloudy water, keep the filter system operating efficiently, and extend the life of your pool liner. Since consistency is key, these resources also show you smart, time-saving techniques for weekly, monthly, and seasonal care. Moreover, you’ll find valuable insights about pool chemicals, routine cleaning, and ways to save on maintenance costs—all tailored to fit the needs of above ground pool owners. Whether you’re a seasoned pool owner or new to pool care, you’ll have the confidence and knowledge to protect your investment and get the most enjoyment from your pool throughout the season.

Visit Your Local Leslie's Pool Supplies Store

Need help getting your pool ready? Stop by one of Leslie’s Pool Supplies stores for expert advice, water testing, and everything you need for a successful pool opening. Our friendly pool professionals are always here to answer your questions, recommend the best products for your above ground pool, and help you save time and money with bundled solutions. While you’re here, take advantage of our free in-store AccuBlue® water testing for an accurate, instant analysis and a personalized step-by-step action plan tailored to your pool’s unique needs. With a wide selection of premium pool chemicals, cleaning gear, and top-rated equipment, we make opening and maintaining your pool simple and affordable all season long. Drop by and discover how easy it is to protect your investment and keep your pool sparkling clean so you can focus on making memories with every swim.

Why visit Leslie's?

• Free In-Store Water Testing: Get accurate results and personalized recommendations.
• Expert Guidance: Our pool professionals can answer all your questions.
• Wide Selection: From chemicals and equipment to accessories, we have it all.

Find your nearest store with our Store Locator and make pool care easy this season!

Still have questions? Call or stop by your local Leslie’s to speak with one of our knowledgeable pool professionals. Don’t forget to bring along a water sample for a free AccuBlue® test, which precisely measures 10 different aspects of water chemistry in your pool.

Check Out Our Pool Opening Video!