How to Open and Close an Inground Pool

Opening and closing your inground pool are two of the biggest pool maintenance tasks you’ll need to complete. Knowing how to open your inground pool properly is essential for a successful pool season. Learning how to winterize an inground pool correctly makes opening it easier during the following season.


Jump To Section:

Opening an Inground Pool
     Preparing to Open an Inground Pool
     How to Open an Inground Pool
Closing an Inground Pool
     Preparing to Close an Inground Pool
     How to Close an Inground Pool
How to Blow Out Pool Lines
Using Antifreeze in Pool Lines


Opening An Inground Pool


Preparing To Open An Inground Pool

Gather the following materials and tools before starting the process of opening an inground pool after winter:

  • A friend to help
  • Soft broom
  • Winter cover cleaner or car wash soap
  • Pool brush
  • Skimmer net
  • A submersible pump (pool cover pump)
  • Thread seal tape
  • Start-up chemical kit or basic pool chemicals, including chlorine
  • Garden hose
  • Pool water test kit or strips
  • Pool shock



How To Open An Inground Pool

1. Clear and Remove Winter Cover

Clean debris off the winter cover using a soft broom and pool brush. Avoid using sharp objects such as a metal rake as this can damage the cover.

Connect a submersible pool cover pump to remove the standing water from the cover.

Disconnect the cover and plugs from all openings or remove water weights. With a friend’s help, carefully remove the pool cover while preventing as much remaining debris as possible from entering the pool.

2. Clean and Store Winter Cover

Lay your pool cover out in a large, flat area. Apply a proper winter cover cleaner or car wash soap and use a soft broom to clean the dirt from the pool cover. Allow the pool cover to dry completely.

Fold up the pool cover and store it in a sealed container or storage bag to minimize the opportunity for bacteria growth.

If water weights were used, empty them and allow them to dry. Store them properly as well.

3. Skim the Pool and Re-Install Your Deck Equipment

Skim any large debris that entered your pool water while removing your pool cover.

Re-install your ladders and pool accessories. Lubricate all bolts to prevent rusting. Raise and install underwater lights from the pool’s bottom if they were removed during pool closing.

4. Take Out Winter Plug(s) and Skimmer Ice Compensator

Remove the winter plugs from the return lines and the openings you installed during your pool closing procedure. Replace them with the correct eyeball or jet fittings. Bubbles appearing after plug removal indicate that the lines were blown out correctly during pool closing.

If antifreeze was used in your pool, blow out all the pipes.

Remove any additional winterizing equipment from the pool, such as the ice compensator from the skimmer. Remove the winter plugs from the bottom, then reinstall the skimmer baskets.

5. Fill Up the Pool

Use a garden hose to fill the pool with water to mid-skimmer level. Use a hose filter to prevent metals and contaminants from entering the pool water.

6. Prepare and Re-Install Your Equipment

Reconnect everything that was disconnected from your filtration system when you closed your inground pool:

1. Install the regular drain plugs in your pump and filter and use thread seal tape to prevent leaks. Your pool heater or chlorinator also has drain plugs.
2. Replace any additional gauges and drains that were removed.
3. Connect the hoses between the skimmer, pump, pool filter and additional equipment such as a chlorinator or heater. Replace any parts that show signs of deterioration.

Open the return side valves. Turn the multiport valve to waste, then replace the air bleeder, sight glass, and pressure gauge. Turn the pump on and allow it to run for approximately one minute.

Turn the multiport valve to filter, then start the pump. Check that there are no unusual sounds and that the pressure isn’t too high for an extended period. If necessary, prime the pump by removing the pump lid, adding water, closing the lid, and then turning the pump back on.

If you have a cartridge filter, remove it and either clean it or replace it.

Allow the pump to continue running with the multiport valve set to filter.

7. Clean Your Pool

Remove any debris with your skimmer, and brush the pool sides with your pool brush to prevent the formation of algae. Take special care to remove any accumulated dirt on the steps, lights, or other crevices.

Vacuum the pool manually to remove any leftover sediment on the pool floor.

8. Balance and Shock the Water

Test your water chemicals using pool test strips or a pool water testing kit. Add any necessary chemicals to bring the levels to the correct range.

It’s recommended that you double shock your pool during pool opening. Use two pounds of chlorine shock per 10,000 gallons of water or 2.5 gallons of liquid chlorine per 10,000 gallons. Be sure to wear safety goggles and chemical-resistant gloves.

9. Wait Before Swimming

Run your pool for at least 24 hours. Continue manually vacuuming out any debris. Retest the water.

Once the pool water is appropriately balanced, and the pool is clear, it’s suitable for swimming.


ingoing pool


Closing An Inground Pool


Preparing To Close An Inground Pool

Gather the following materials and tools before starting the process of closing an inground pool for the winter:

  • Winter cover
  • Water bags
  • Skimmer plugs
  • Return jet plugs
  • Pool chemicals
  • Air compressor or a shop vac
  • Pool brush
  • Telescoping pole
  • Pool water test kit or strips
  • Pool shock

Check your winter cover and water bags for rips, tears, or leaks. Inspect your plugs for cracks or holes.


How To Close An Inground Pool

1. Clean and Prepare Your Pool

Attach a pool brush to a telescoping pole to clean your pool walls and floor. Manually vacuum your pool.

Clear the pool of any flotation devices, equipment, and pool accessories. Clean, dry, and store them properly for the winter.

2. Test and Balance the Water

Test and balance your pool water to make opening your pool easier next season.

If your pool is at risk for algae, use an algaecide. Use a metal sequestrant if you have high amounts of metals in your water. Use a pool enzyme product to boost your pool and help algaecide attack organic contaminants.

3. Complete a Shock Treatment

Complete a final shock treatment before closing your pool for the season. Be sure to wear safety goggles and chemical-resistant gloves.

Retest your pool water the following day to ensure it’s balanced.

4. Lower the Pool’s Water Level

Note: This step is unnecessary if you live in a warm, dry climate.

Drain the pool’s water level to just below the return lines to prevent freeze damage and overflow. To do so, select the waste setting on your pump and allow the water to exit until it reaches the desired level. Follow the manufacturer’s recommendations on your winter cover for the exact level to drain the water down to.

5. Backwash and Clean the Filter and Pump

Backwash and clean your filter and pump.

6. Prepare Filters and Pumps

Disconnect your pump and filter and allow the pump to drain thoroughly. If there are any quick disconnect fittings or unions, unscrew them to ensure all water is removed.

Remove the drain plug and empty all the water. Store the plug somewhere safe until you reopen the pool in the spring. After draining your pump, turn it on for one second to remove any remaining water. Leaving it running for too long can create damage.

Leave the backwash valve open, then clean the pool filter and drain the filter tanks. Follow specific instructions for the type of filter you own. Remove all water from the multiport valve with a shop vac or compressor.

Remove jet fittings. Store the pump, filter, and any additional parts in a dry location for the winter.

7. Prepare Your Pool Heater (If Applicable)

Turn off your pool heater and drain it completely. Remove the drain plugs, then use a shop vac or compressor to clear any remaining water from the lines. Leave the drain plugs out and store them somewhere safe for next season.

Consult your manufacturer’s instructions to determine whether the heater tray should be removed.

8. Drain and Blow Out the Lines

Use an air compressor or shop vac to blow out your water lines. When each line is clear of water, use a specific plug to seal the opening and prevent water from re-entering.

If there’s a main drain line, create an airlock by blowing out the line until bubbles appear at the drain. Plug the line by closing the valve.

9. Plug the Skimmer Hole

Use one of the following options to plug the skimmer hole to protect it throughout the winter:

Skimmer Plate: This plastic plate covers the mouth of the skimmer to prevent water from entering the skimmer. Although it will leave the water level up during the winter season, it’s only recommended for use in pools with pool liners.

Gizzmo: A Gizzmo is a hollow tube that collapses if water enters the skimmer and freezes.
Remove skimmer baskets, then lower the water below the mouth of the skimmer. Use a shop vac or compressor to blow out all the skimmer lines. Install either a skimmer plate or Gizzmo. If using a Gizzmo, ensure you place tape on the threads before installing to ensure a tight seal.

10. Install Your Pool Cover

There are two ways to install your winter pool cover depending on the type of cover your own:

Installing a Regular Winter Pool Cover

Lay your pool cover over your pool and place water bags along the pool’s perimeter. Place the water bags through the pool cover loops and into the corner pockets for added strength.

Avoid overfilling the water bags; if the bags are too full, they could burst when the water inside freezes and expands.

If the cover dips toward the middle of the pool, it hasn’t been installed correctly.

Installing a Pool Safety Cover

Use previously placed anchors on your pool deck to hold the cover in place instead of water bags. Check the condition of the anchors – they should be flush with the pool deck.

Attach the cover to the anchors by following the manufacturer’s instructions. To make opening your pool easier in the spring, perform light maintenance over the winter months by removing debris from the cover with a leaf blower.



How To Blow Out Pool Lines

1. Take out return fittings, skimmer baskets, and drain plugs.
2. Turn the multiport valve to recirculate.
3. Position the valve in front of your pump to the skimmer line.
4. Connect your air compressor to the pump’s drain plug, using an adapter if necessary. Allow air to enter the system. Check that bubbles are escaping from the return lines and skimmer.
5. Use a shop vac to remove all water from the skimmer. Place a skimmer plate or Gizzmo in the skimmer’s bottom.
6. Install a rubber plug in each return line after the air bubbles exit. For colder climates, you may need to install straight pressure plugs in the return lines.
7. Position the valve in front of your pump to the main drain setting, then watch for bubbles exiting the main drain in the deep end.
8. Set the pump valve back to the skimmer line, then power off your air compressor.
9. Install a plug inside the pump in case the valve leaks.

If you’re a pool owner in a warmer climate, you don’t need to blow out your lines. However, you’ll still have to remove the return fittings from your jets and the line for your automatic cleaner, plus clean and remove your skimmer baskets.

If you’re a saltwater pool owner, remove your saltwater generator, then drain and store it properly. Turn off the power and gas to the heater. Store any controllers, robotic cleaners, and other electronics inside.

Using Antifreeze In Pool Lines 

If you blow out your lines correctly, they won’t freeze. If you’re worried that you haven’t removed every drop of water from the lines or want to close your pool in a hurry, you can use swimming pool antifreeze.

Select an antifreeze rated down to 10°F (-12°C). Be sure to use an antifreeze designed for pools, not vehicles. Antifreeze products designed for pools are non-toxic.