You are ready to shut down the pool for the winter season. You’ve cleaned the pool and balanced the water. It’s time to winterize those plumbing lines and get the pool covered. So now you’re wondering how much water you should drain from the pool as part of your winter process.
The short answer is it depends. How you manage the rest of your winterization process will determine if you need to drain any water from the pool and how much to drain.
When draining a pool to close or winterize it, the standard suggestion is to drain approximately 4-6 in (10-15 cm) from the top of the pool or 2-3 in (5-7 cm) below the skimmer. Some people choose not to drain any water from their pools, while others will drain more than what is suggested because of the type of cover they use or the weather in their region.
Here is a more in-depth look at why you should (or shouldn’t) drain water from your pool during the winter.
Why Would You Drain Water?
The goal of lowering your pool’s water level is to keep water from re-entering the pipes and freezing. Water expands when it freezes and can cause the pipes to crack, leading to water leaks and expensive repairs.
Draining the water below the skimmer level, typically 4-6 in (10-15 cm), keeps water from re-entering the drain system and prevents damage to the plumbing. If you live in areas with heavy rainfall during the winter months, you may want to consider draining the water to a slightly lower level to account for the precipitation. Make sure you do not lower the water by more than 18 in (45 cm).
It is important to note that you do NOT want to completely drain your pool – whether above ground or in-ground. Removing all water from an above-ground pool can cause it to collapse. The weight of the water actually helps it to maintain its shape and protects the liner. Draining an in-ground pool or fiberglass pool completely can cause it to crack or pop out of the ground.
Special Considerations: Pool Lights and Ceramic Tiles
If you have lights in your pool, make sure they are either completely covered with water or completely uncovered. Leaving water that partially covers the lights can add extra pressure in the event of a freeze and cause the light covers to crack.
Ceramic tiles near the surface of the pool can crack if the water freezes. So, you will need to lower the water level below the tiles even if you’re using a skimmer cover and plugs for the plumbing lines.
You can also use an “air pillow” which takes the pressure off of the pool walls when the surface freezes over.
What Happens If You Don’t Drain Any Water?
Draining water from your pool during the winter isn’t required. If you want to maintain the pool at its normal water level, you will need to use a few tools to help prevent water from getting into your pipes during the colder weather.
- Use a skimmer cover to keep water from entering the skimmer. This prevents water from getting into the pipes and freezing, causing cracks.
- You’ll also need a Gizzmo to insert into the skimmer to prevent the skimmer cracking when the water freezes.
- Use plugs for any return jets or valves to prevent water from entering those areas.
- Add antifreeze to the pipes and skimmer.
- And use an “air pillow” on the surface of the pool.
This is a gizmo and goes in the skimmer to prevent damage when the water freezes and expands.
This is a winterizing plug. Use it to block and plug your lines for the winter season.
If you use these items to protect your pipes, then it is not necessary to drain the water below the skimmer.
You may still want to consider using a pool cover to keep debris out. Follow the recommended directions based on the type of pool cover you choose (mesh or solid). We’ve outlined these below.
If you’re not sure if you should add antifreeze, we have a whole article on this.
Can I Drain All The Water And Just Start Over Next Season?
It is not ever a good idea to remove all of the water from your pool for an extended period of time! Leaving your pool without water can cause damage to the pool’s liner or to the exterior pool structure.
● For Above-Ground Pools
Above-ground pools do run the risk of collapse, so it’s important not to drain all the water from the pool. If your above-ground pool has a removable pump and skimmer, you won’t need to remove water from the pool since the goal of lowering the water level is to prevent water from entering those lines. But you will need to drain those lines and also drain the pump and filter.
● For In-Ground Pools
If all the water is removed from an in-ground pool, you have the risk of several different issues. First, the walls can crack, causing expensive structural damage. Second, the pressure in the ground surrounding the pool can cause the pool exterior to lift out of the ground. Check out our article Should You Drain Pool Below Skimmer or Return Jets? to check how to safely drain your pool.
How Do I Remove The Water So It’s Below The Skimmer?
If you have a main drain plug or valve, you can open this to lower the water levels. You can use the pool pump, turned to the drain/waste setting, to flush water from the pool.
Make sure your main drain is not blocked though.
However, it is recommended to use a submersible pump that can also be placed in the pool to remove water.
Use a submersible pump like this to drain water below the skimmer of a pool. It’s important to use a pump like this to avoid sucking air into the pool pump.
Remember that you did just add chemicals to the water for winterization, so be sure to pay attention to where the excess water is draining. Pool water can be harmful to wildlife or contaminate your groundwater.
A cover can be important to keep debris out of the pool during the winter months and is recommended for both above-ground and in-ground pools.
If you use a mesh cover for either an above-ground or in-ground pool, drain the water lower than the recommended 4-6 in (10-15 cm) to allow for rain or snow to enter the pool and increase the water level. The amount you lower the water should be based on the expected precipitation for your area over the winter months. Keep in mind that you may also have to remove more water during the winter if precipitation is heavier than normal.
To protect the pool’s liner, you should NOT lower the water by more than 18 in (45 cm).
A solid cover prevents water from seeping through the cover for both above-ground and in-ground pools. So, it is not necessary to drain the water as much as with a mesh cover. The standard 4-6 in (10-15 cm) should be sufficient if the water line is below the skimmer.
If you’ve got a solid cover you may need a pump to help remove water that builds up on top of it. This keeps the cover from sagging or ripping with the weight of the water or snow/ice.