Preparing your swimming pool for winter is a critical step to ensure its longevity and performance in the next season. One of the most common questions pool owners ask is, how far below skimmer to drain pool for winter? The answer to this question depends on various factors including pool type, climate, and equipment. In this comprehensive guide, we will delve into the best practices for winterizing your pool and specifically address how below the skimmer the water level should be to protect your pool from cold weather damage.
Understanding the Importance of Draining a Pool for Winter
Before we dive into the specifics of how far the water should be drained below the skimmer, it’s essential to understand why this step is crucial. Draining a pool before winter serves several important functions:
- Prevents freeze damage
- Protects pool equipment
- Minimizes algae growth and water discoloration
When water freezes, it expands. If the water level in your pool is too high when the temperature drops, this expansion can cause significant damage to your pool’s structure, plumbing, skimmer, and even tile line. Proper winterization not only protects your investment but also ensures that opening your pool in the spring is a smoother process.
Types of Pools and Winterization Needs
The type of pool you own significantly affects how much you need to drain it for winter. There are primarily two types of residential pools: in-ground and above-ground. In this article, we’ll focus mainly on in-ground pools, as they often involve more complex winterizing techniques, including the draining of water below the skimmer.
1. In-Ground Pools (Vinyl, Concrete, Fiberglass)
Most in-ground pools require partial draining, mainly to below the skimmer level. This helps protect internal components such as:
- Skimmer box
- Return jets
- Pump and filter system
2. Above-Ground Pools
Above-ground pools usually drain completely for winter, especially in climates where temperatures drop below freezing regularly. The structure is not as robust as in-ground pools and can collapse or warp if water freezes inside.
Key Rule: How Far Below the Skimmer to Drain Your Pool
The golden rule for most in-ground pool owners is to drain the water approximately 6 inches below the skimmer inlet. This depth ensures that any freezing does not affect the skimmer and associated plumbing, which are among the most vulnerable parts of the pool system.
Note: This measurement is generally sufficient, but it may vary slightly depending on your pool’s design and the manufacturer’s recommendations. Always check for model-specific guidelines.
Step-by-Step: How to Determine the Correct Drainage Level
Here’s how to find the optimal level for draining before winter:
- Locate the skimmer inlet on your pool wall
- Measure 6 inches below this point
- Drain the water so the final level is at or slightly below this mark
If you’re using a cover, some experts recommend draining a bit further to allow the weight of the cover and winter debris without submerging water into the skimmer area.
Draining Too Far Can Cause Problems
Draining the pool more than required can expose the pool liner or render your pool’s structure vulnerable. In vinyl liner pools, excessively low water levels can create a vacuum effect causing the liner to shrink. Fiberglass and concrete pools might risk hydrostatic pressure issues from groundwater, which can cause the pool to lift or crack.
Climate Considerations: How Colder Temperatures Affect Pool Drainage
Your local climate plays a massive role in how far you need to drain the pool. If you live in a moderately cold region where freezing is occasional, you may not need to drain as much as compared to regions with harsh winters.
Cold Climate: Zones Prone to Freezing
In areas where freezing is frequent and prolonged, the risk is higher. It’s important to ensure water doesn’t remain in the skimmer box or attached plumbing. A general best practice includes:
- Draining down 6–8 inches below the skimmer
- Blowing out plumbing lines
- Placing a winter cover with proper fastening
Mild Climate: Where No Freezing Occurs
If you live in a region where freezing temperatures don’t typically happen, you may not need to drain the pool significantly. Just lower the water level enough to:
- Install a safety cover
- Prevent debris saturation
In these conditions, draining just 2–4 inches below the skimmer may be sufficient.
Step-by-Step Guide to Winterizing Your Pool
Draining the pool is only part of the complete winterization process. The following steps ensure your pool survives the cold season without damage.
Step 1: Test and Balance Your Water
Before you start the drainage process, have your pool water tested. The chemical levels should be balanced to inhibit algae growth and corrosion during the inactive season.
| Chemical | Recommended Level |
|---|---|
| Chlorine | 1–3 ppm |
| pH | 7.4–7.6 |
| Alkalinity | 80–120 ppm |
| Calcium Hardness | 200–400 ppm |
Step 2: Clean Your Pool
Thoroughly brush the walls and floor of the pool, vacuum debris, and empty the skimmer and pump baskets.
Step 3: Lower Water Level
Now is the time to lower the water level. As a rule, lower the surface level about 6 inches below the skimmer intake. This helps protect the skimmer and prevents freeze expansion from damaging the internal components.
Step 4: Drain the Equipment and Plumbing Line
Shut off the pool pump and filter system. Disconnect the equipment and blow out all plumbing lines using a pool air compressor. Ensure all water is removed from the pipes to prevent freezing and cracks.
Step 5: Add Winterizing Chemicals
Adding a pool winterizing chemical kit or winter algaecide is crucial. These chemicals prevent algae and bacteria from growing during the cold months.
Step 6: Install Winter Cover and Use Air Bags (if applicable)
A sturdy winter cover is essential. Secure the cover with water bags or anchors to prevent wind and debris from damaging it. In vinyl pools, installing air pillow bags under the cover may help absorb the weight of ice or snow.
Common Myths About Draining Winter Pool Water
There’s no shortage of advice when it comes to winterizing your pool — but not all of it is accurate. Let’s break down some myths and the truths behind them.
Myth 1: You Must Completely Empty Your Pool
Wrong! Although some areas with extremely harsh winters may warrant complete draining, for most in-ground pools, partial draining to about 6 inches below the skimmer is sufficient.
Myth 2: Draining Below Skimmer Alone is Enough
This is a partially correct assumption but requires context. The key is not just the water level but also protecting the plumbing lines and covering the pool appropriately to avoid damage.
Myth 3: No Need to Test Water Before Winterization
False. Unbalanced water can cause staining, scaling, or etching of the pool surfaces. It’s vital to test and adjust the water chemistry ahead of drainage.
Factors That Influence the Right Drain Level
The exact number of inches below the skimmer is not always a fixed rule. Here are some additional factors that determine how low to drain your pool:
1. Type of Pool Cover
A solid winter cover keeps debris out but also allows water to pool on top. If excess water collects over the cover and isn’t removed, it can spill into the skimmer. Thus, draining a bit lower than 6 inches may be helpful.
2. Skimmer Location and Depth
Some pool skimmers are positioned toward the bottom of the pool wall for aesthetic or functional reasons. In such cases, the recommended 6-inch below mark should still apply in relation to the skimmer itself, but the final drain level may appear shallower visually.
3. Winter Weather Forecast
If you expect an unusually heavy winter snowfall or extended freezes, consider lowering the water even more (up to 12 inches below the skimmer). This can add an additional layer of protection.
Tools and Equipment Needed for Draining and Winterizing
Before you begin, gather the necessary tools and equipment to carry out the task effectively:
Using the right tools can save time, protect your pool, and ensure a more efficient process.
Differences Between Saltwater and Chlorine Pool Drain Levels
Saltwater pools function differently than traditional chlorine pools and have specific maintenance needs during winterization.
Saltwater Pools
Saltwater pools often require a slightly lower water level due to the salt chlorinator system. Draining 4–6 inches below the skimmer usually works, but always refer to the manufacturer’s instructions.
Chlorine Pools
For chlorine pool users, regular winterizing applies. Drain to about 6 inches below the skimmer, unless local climate dictates otherwise.
Conclusion: The Right Drain Level Ensures Pool Longevity
Knowing how far below skimmer to drain pool for winter is a vital aspect of effective pool maintenance. While the standard guideline is to drain approximately 6 inches below the skimmer intake, you must consider pool type, climate conditions, and equipment setup to determine the most appropriate level for your own pool.
Whether you’re a new or seasoned pool owner, taking the time to properly winterize your pool — including getting the water level right — can significantly extend its functional life and reduce costly damage.
By following this guide and implementing the correct winterizing techniques, you’ll be ready to enjoy a clean, functional pool when the warmer days return in the spring.
If you’re unsure about your specific pool’s needs, consult a professional pool technician. They can provide site-specific advice based on your pool structure and climate zone.
Why is it important to drain pool water below the skimmer for winter?
Draining your pool water below the skimmer is a crucial step in winterizing your swimming pool. When water remains in the skimmer during freezing temperatures, it can expand as it freezes, leading to cracks in the skimmer lid, throat, or even the pool wall. This damage can be costly to repair and may compromise the integrity of your pool structure. Properly lowering the water level prevents this type of freeze-related damage and ensures the pool remains in good condition throughout the colder months.
In addition to protecting the skimmer, lowering the water level helps safeguard the pool’s plumbing system. Water left in the lines can freeze, expand, and cause pipes to burst or fittings to break. By draining water below the skimmer and blowing out the lines properly, you eliminate standing water in vulnerable areas. This process is essential for both above-ground and in-ground pools, though the specific steps can vary depending on the pool type and local climate conditions.
How far below the skimmer should I drain my pool for winter?
As a general rule, you should drain the water level to approximately 6 to 8 inches below the skimmer opening. This depth ensures that any water remaining in the skimmer area has sufficient space to expand without causing damage. If you live in a region with particularly harsh winters or extended periods of freezing temperatures, you may want to lower the level even further, especially if your pool pump and filter system are turned off for the season.
It’s important to strike a balance—draining the pool too low can expose vinyl liners or fiberglass surfaces to the elements, which may lead to warping or cracking due to pressure loss. Always follow recommendations based on your specific pool type. For in-ground pools, you should also maintain enough water to counteract hydrostatic pressure from groundwater, which can cause the pool to pop out of the ground if empty. Consult your local pool professional if you’re unsure how far to drain your specific pool.
Can I drain my pool too low for winter?
Yes, draining a pool too low can lead to serious structural issues, especially for in-ground pools. If the water level drops below the main drain or the pool becomes completely empty, the pressure imbalance caused by groundwater can result in the pool lifting or shifting from its original position. You may also risk damaging the vinyl or fiberglass liner if it’s not properly secured and supported. In some cases, pool walls could collapse due to the lack of internal water pressure.
Additionally, draining the pool too far can expose sensitive components like light niches and return jets to freezing temperatures and debris buildup. These areas are still vulnerable to damage even if the water level is reduced. A good guideline is to keep water just below the skimmer while ensuring all plumbing lines are properly winterized. Always store winter covers correctly to maintain water levels and protect the pool structure, and consult the pool manufacturer or a professional winterizing service if you’re uncertain about what’s appropriate for your system.
What tools and methods are needed to drain a pool below the skimmer?
To effectively drain your pool to the appropriate winter level, you’ll generally need a submersible pump, a garden hose long enough to reach a safe drainage area, and a reliable way to measure the water level. Some pool owners also use a pool cover pump later in the season to manage rain or melting snow accumulation. A wet/dry vacuum can also be used for smaller amounts of water removal, especially in the final stages.
The process begins by turning off the pool pump and filtering system and ensuring the equipment is properly winterized. Then, connect the submersible pump and begin draining water until the level is at least 6 to 8 inches below the skimmer. Always direct water away from the pool structure to avoid seepage or property damage. Use a tape measure or marked pole to confirm you’ve reached the correct depth. Once drained, secure the pool cover and check that all skimmer and return line plumbing are protected against freezing.
How does climate affect how much I should drain my pool for winter?
Your geographic location and regional climate have a significant impact on how much you should drain your pool for winter. In areas with mild winter conditions and minimal freezing, it may not be necessary to drain the pool significantly below the skimmer. However, in regions where freezing temperatures are common, draining the pool further and winterizing the plumbing system becomes critical to avoid damage caused by ice expansion.
Local building codes may also dictate how pool water should be managed during the off-season. For instance, in the northern United States and Canada, in-ground pool owners are typically advised to drain pools much lower than those in southern regions. Additionally, pools in areas of heavy rainfall may want to drain slightly further to account for rainwater accumulation during winter. Always tailor your winterizing practices to your climate zone and consult with local pool professionals for ideal winter preparations.
What should I do with the skimmer after draining the pool?
After draining the pool below the skimmer, you should winterize the skimmer and its internal plumbing to protect against freeze damage. This involves removing the skimmer basket and drain plug, blowing out the line with an air compressor, and installing a pool winterizing plug or Gizzmo. Once installed, these devices help absorb the pressure of freezing water in case any moisture remains in the line.
It’s also advisable to place a skimmer cover or insulating foam over the skimmer opening to provide additional protection and to keep debris out during the off-season. If your system includes automatic pool cleaners or additional skimmers, each should undergo the same winterization process. By properly sealing and protecting the skimmer, you prevent costly repairs and ensure the pool is ready for use when warmer weather returns.
How does proper winter pool drainage affect pool maintenance the following season?
Proper winter drainage directly impacts the ease and efficiency of spring pool opening. If the pool is drained correctly and all lines and equipment are winterized, there is less risk of freeze damage, which means fewer repairs and less maintenance to get your pool back in working order. Starting the season with a well-maintained water level also reduces the effort needed to balance pool chemistry and replace lost components.
Moreover, proper drainage helps maintain pool cover integrity and prevents the buildup of algae or debris in hard-to-reach areas such as the skimmer. This facilitates a cleaner and smoother reopening process, allowing for quicker startup and less time spent on chemical adjustments or equipment fixes. In the long run, careful winter pool drainage preserves the pool’s structure, extends equipment life, and ensures a more enjoyable swimming season.