Blog Header Logo

How to Open Your Pool in Spring

The arrival of spring means lots of our seasonal favorites – the beauty of blossoming plants and trees, longer-lasting sunshine, and warmer temperatures. For pool owners, spring’s arrival means it’s time to open your pool for the season! But just because the sun is shining doesn't mean the pool is quite ready for swimmers. With just a little effort, these steps will help you on your way to a clean, safe, healthy, and swim-ready pool.

When should you open your pool? If you’re wondering when is the right time to open an above ground pool or an inground pool, it all comes down to the weather. No matter what type of pool you have, we recommend opening the pool when daily high temperatures are consistently above 70ºF.

The steps for opening your pool are listed below. Highlights include:

Remove pool cover to open pool

Clearing, removing, and storing your pool cover.

Add water to pool during opening

Filling your pool water to regular levels.

Pool Water Circulation is important to open a pool

Reconnecting and turning on your pool equipment.

Balance pool water while opening the pool

Testing and balancing your pool water.

Leslie's Pool Shock helps with pool opening

Shocking your pool.

DIY TIP: Looking to simplify your pool opening process this year? Just purchase a Pool Opening Kit! Each kit comes with all the essentials you'll need to treat your pool water  at pool opening time. In the kit, we’ve included pool shock, algaecide, clarifier, and stain and scale prevention. Deluxe and Premium kits also include Perfect Weekly Start-Up, a triple action phosphate remover and enzyme blend. Just choose the right kit for your pool size, up to 35,000 gallons. For larger pools, use multiple kits.

1. Drain and Clean the Pool Cover

Whether you have a winter cover or solid safety cover, you will need to remove the water off the top of the cover before taking it off.  If there is substantial water, you may want to use a cover pump to do the work for you. Afterward, sweep or use a blower to remove all leaves and other debris from the cover. You don't want all that stuff landing in your pool when the cover comes off!

2. Remove the Pool Cover

When removing the pool cover, you may need a second person to help if you have a large pool or are working with a safety cover. Try to prevent remaining debris or dirty water from falling into the pool as you remove the cover. If a bit of debris ends up in the pool, that’s OK. You will have to vacuum and shock the pool before you start swimming, anyway. But less debris in the water will make the whole process go much more quickly as you work to open your pool.

3. Clean and Store the Pool Cover

After you remove the cover, lay it out, brush off any remaining debris, spray it down with water, and then let it dry. If necessary, you can use a vinyl-safe cleaning product to help remove stuck-on dirt and debris. When the cover is completely dry, sprinkle one side and then the other with talcum powder or Leslie’s Alkalinity Up to prevent mold and mildew. Fold the cover loosely, and store it in a cool, dry place.

NOTE: If you did not winterize your pool for freezing conditions, skip ahead to Step 6.

4. Reconnect the Pool Equipment

If you prepared your pool for freezing temperatures, you will need to reinstall your pool equipment when you open the pool. This includes reconnecting your filter, pump, heater, and anything else you may have disconnected on your equipment pad or inline pool plumbing. For above ground pools, you will need to reconnect the flexible plumbing lines to the pool equipment and skimmer.

Once connected, double check that all drain plugs are replaced in your pool pump, filter, heater, booster pump, pool cleaners, and any other pool equipment.

5. Remove Winterizing Plugs from Skimmer and Return Lines

Don’t forget to remove any winterizing plugs you used in your skimmer and return lines. Now you can reconnect any return valve fittings that you removed last winter. If you used non-toxic pool antifreeze at pool closing time, discharge it to waste or backwash (sand or D.E. filter), or use a wet/dry shop vac to remove it through the skimmer (cartridge filter) before removing the winter plugs.

6. Raise the Water Level Back to Normal

Use a garden hose to fill the pool back to its normal water level. This is typically at about the middle of the skimmer opening or halfway up the tile.

7. Turn the System Back On

Prime the pump and turn on the circulation and filtration system. If you have an air relief valve on your pool filter, open it to bleed the air from the system. Once water spurts out, close the air relief valve. Check all around the equipment pad for leaks or unusual noises. If you notice major issues, turn the system back off until you can make the necessary repairs.

8. Add Stain and Scale Prevention Chemicals

After a long winter off-season, metals such as copper and iron may have concentrated in your pool water or fallen out of solution. When you open the pool, add 1 liter of Metalfree for every 20,000 gallons of water to prevent metals from causing stains or discoloration in your pool. Or, if you purchased a Leslie's Pool Opening Kit, add Stain & Scale Prevent Start-Up. Apply around the perimeter of the pool, and allow the circulation and filtration system to run for at least 2 hours.

Each week during swimming season, continue to use Leslie's Stain & Scale Prevent according to label directions. This will avoid staining issues and scale buildup in your pool all summer long.

9. Test the Pool Chemistry

Once the circulation system has been running for a few hours, test your pool water for pH, Total Alkalinity (TA), and Chlorine levels with a test kit or test strips. Ideal levels should be:

  • pH: 7.4 to 7.6
  • Total Alkalinity: 80 to 120 ppm
  • Free Available Chlorine: 2.0 to 4.0 ppm
  • Calcium Hardness: 200-400 ppm

DIY TIP: You can also bring a water sample to your local Leslie’s for a free water test.  Our pool experts will help you get the most comprehensive and precise chemistry analysis with the Leslie's AccuBlue® water test, and you'll receive a customized step-by-step plan to balance your water.

10. Balance the Water

Balancing your water properly is a necessity for safe and healthy swimming after you open the pool. You can control the pH and chlorine levels in your water by first adjusting the Total Alkalinity (TA). As with all pool chemicals, always read and follow the product label's detailed dosage and application instructions.

Total Alkalinity

Ideal TA levels depend on the type of primary sanitizer you're using. When using dichlor, trichlor, or bromine as your primary sanitizer, the ideal range is between 100-120 ppm. For a salt water chlorine generator, most manufacturers recommend TA levels between 80-120 ppm.

If TA is too high, you can use Leslie’s Dry Acid to lower the levels to the ideal range. To lower the TA by 10 ppm, add 1.5 pounds of Leslie’s Dry Acid for every 10,000 gallons of water.

If TA is too low, add Leslie’s Alkalinity Up or Leslie's Soda Ash to increase TA Levels in the water. Adding 1.5 pounds of Alkalinity Up will increase the TA of 10,000 gallons of water by 10 ppm. Wait at least 4 hours after adding adjusting TA before retesting the water.


Once the TA is within its proper range, test and adjust the pH balance. The acceptable range is 7.2-7.8, and the ideal range is 7.4-7.6 for pH.

If the pH level is above 7.8, add small doses (2 cups at a time) of Leslie’s Dry Acid. Wait at least 2 hours with the circulation system running, and retest before adding more acid as necessary.

If the pH level is below 7.4, add 6 ounces of Leslie’s Soda Ash, which should increase the pH level of 10,000 gallons of water by about 0.2 ppm. Wait 4 hours with the system running and retest the water before adding more Soda Ash. If the pH is below 7.0, follow product label directions for proper dosing, or go to your local Leslie's store for additional testing.

Calcium Hardness

Your pool’s Calcium Hardness (CH) level should always be above 150 ppm. If the CH level is too low, bring it up by adding Leslie’s Hardness Plus. Using 1.25 pounds will increase the CH of 10,000 gallons of water by 10 ppm. The target is the ideal range of 200-400 ppm.

DIY TIP: Don’t add Leslie’s Hardness Plus on the same day as Leslie’s Soda Ash or Leslie’s Alkalinity Up. Wait at least a day before adding Leslie’s Hardness Plus, or you may have issues with cloudy pool water and increased scaling on pool surfaces.

11. Brush and Vacuum the Pool

After your pool chemistry is adjusted, thoroughly brush and vacuum your pool to remove any remaining dirt and debris, giving special attention to areas like the pool steps, ladders, lights, or other crevices.

Next, run the pool pump overnight. Your pool’s filtration system will remove the rest of the suspended dirt and debris left over after brushing and vacuuming your pool.

13. Shock the Pool

Shocking the pool will eliminate any remaining germs and contaminants in your water. Shock the pool following the label instructions, using a chlorine-based pool shock, such as Leslie’s Power Powder Plus 73 or Leslie’s Chlor Brite. Always read the instructions to determine how much shock to add to your pool.

If you have an automatic pool cleaner, you can reinstall the cleaner 24 hours after shocking the pool.

14. Add Specialty Pool Chemicals

This is a good time for a reminder! It's extremely important to read and follow all product label instructions, especially as it relates to storage, handling, dosing, and wait times before swimming or adding other chemicals. Remember to NEVER mix chemicals together! To finish getting your pool ready for swimming season, we recommend the following:

Algae Control

The day after shocking the pool, add the recommended dosage of Leslie's Algae Control, and allow the circulation system to run for at least 2 hours.


If you're having issues with cloudy water, an application of Leslie's Ultra Bright Advanced will coagulate the smallest particles in your water, boosting the efficiency of your filter and helping clear up the water faster. Run the circulation system for at least 4 hours. Check the filter pressure, and clean the filter if necessary to keep it running efficiently.


Enzymes work to break down non-living organic contaminants, helping your sanitizer work more efficiently and keeping oily residues out of your pool. Some enzyme products, like those listed below, also contain phosphate removers to fend off algae.

Shake up a bottle of Perfect Weekly Start-Up (Deluxe and Premium Pool Opening Kits) or Pool Magic + Phosfree, and add the proper amount into your skimmer while the pump is running. At start-up, we recommend running the pump continuously for 48 hours after applying enzymes. During season, use Leslie's Perfect Weekly each week to help keep your pool water crystal clear all summer.

Download or print Leslie's Pool Opening guide for quick and easy poolside reference. Click HERE for your free copy!

Got Questions? Leslie's Has Answers.

Have questions, or need help? Leslie’s is the go-to resource for all your spring pool needs and pool opening supplies. We can help make your pool opening process so smoothly this year with one of our specialized Pool Opening Kits. These kits contain just the right amount of chemicals needed to open the pool and treat the water. It's a must-have item for clean, clear, and safe pool water at opening time.

Once you've finished opening your pool, bring a water sample to your local Leslie's store to take advantage of our free AccuBlue® water test. You'll get a professional analysis on 10 aspects of water chemistry to ensure your water is perfectly balanced. If anything is out of range, you'll receive detailed step-by-step recommendations to correct the issue and get your pool swim-ready.

If you are a new pool owner, or if you prefer to have someone else open the pool for you, it's easy to schedule your pool opening service online or in-store. Leslie’s Certified Service Technicians are Leslie’s employees, not third-party contractors, so you can be confident that they are well-trained pool professionals. They can answer any pool care questions you might have, as well as provide tips to make it easier to open your pool and get it in tip-top, swim-ready condition. To learn more about Leslie's Pool Opening Service, check out this blog post or visit your local Leslie's.

Essential Pool Opening Chemicals

Leslie's Premium Opening Kit Bundle

Shop Opening Kits

Leslie's Pool Shock

Shop Pool Shock

Leslie's 3 inch Jumbo Tabs

Shop Chlorine

Facebook  Twitter  YouTube  Instagram