Protecting your swimming pool during off-season or when it’s not in use is crucial for maintaining its longevity and cleanliness. Pool covers play a significant role in this process by preventing debris, sunlight, and contaminants from affecting the water. However, a common debate among pool owners is whether or not they should put water on top of the pool cover. While this practice may seem counterintuitive, it’s a topic that requires careful consideration based on pool type, climate, cover material, and safety concerns.
In this article, we will dive deep into the pros and cons of adding water to pool covers, explain the best practices for different cover types, and provide actionable tips on how to do it safely and effectively. If you’re wondering, “Do you put water on top of a pool cover?” then you’ve come to the right place.
Understanding the Purpose of Pool Covers
Before answering the question of whether to add water to a pool cover, it’s essential to understand the primary functions of pool covers:
- Prevent debris entry – Covers stop leaves, dirt, and insects from entering the pool.
- Reduce evaporation – Especially during hot weather, pool covers minimize water loss.
- Maintain water temperature – Solar covers, for example, retain heat and reduce energy costs.
- Limit chemical usage – By blocking sunlight and reducing evaporation, covers help preserve chlorine levels.
But the role of a pool cover changes depending on whether it’s a safety cover, a winter cover, or a solar cover. Each has different maintenance needs. So, does water apply equally to all of them?
Why Would You Put Water on Top of a Pool Cover?
Putting water on a pool cover is mostly a consideration for winter pool covers. The logic behind this seemingly odd idea is based on practicality:
Tension and Stability
Winter or mesh safety covers are designed to span over the entire pool and are held in place by water bags, anchors, or springs. However, adding water (or using solid covers with water pockets) helps ensure the cover doesn’t flap or shift due to wind, which can damage the cover and allow water to pool unevenly.
Debris Management
When water is added to the cover in designated water tubes or directly (on solid covers), it helps hold the cover in place—preventing leaves, twigs, and dirt from blowing underneath. This simplifies cleanup when the cover is removed in the spring.
UV Protection
Water on a pool cover (especially in transparent or translucent bladders) can offer additional UV protection by refracting sunlight and reducing the degradation of the cover material.
However, not all cover types benefit from added water. In fact, some could be damaged by it. Let’s explore the ins and outs of water use on different cover types.
Pool Cover Types and the Role of Water
Understanding the type of pool cover you have is essential when answering the question: “Should you put water on top of a pool cover?”
Solid Winter Pool Covers
Solid covers are made of thick, heavy-duty vinyl designed to block out all sunlight and debris. They’re usually used in areas with heavy rainfall or snowfall.
Do You Add Water?
Typically, a solid cover does not require water on top. In fact, standing water on a solid cover may cause safety risks or strain the cover and support system. However, these covers often have drain plugs or grommets to allow for water runoff.
Mesh Winter Pool Covers
Mesh covers, often made from woven polypropylene, allow rainfall or melting snow to pass through while keeping large debris out. These covers are taut and are usually fastened around the pool’s edge.
Do You Add Water?
Yes, it’s common and recommended to place water bags or tubes filled with water on top of mesh pool covers. These act as weights to keep the cover tight, helping it endure harsh winter conditions without sagging or tearing.
Solar Pool Covers
Solar covers, sometimes called “solar blankets,” are made of a bubble-like vinyl sheet that floats on the pool’s surface and absorbs sunlight.
Do You Add Water?
No—water should never be placed on a solar cover. Since this cover floats on the water, adding water to it would cause it to sink and reduce its heating and evaporation control functions.
Automatic and Manual Safety Covers
Safety covers, usually solid and tightly secured with tracks or anchors, are designed for safety and pool preservation.
Do You Add Water?
In most cases, water is not required on these covers. High-quality safety covers are under tension with a track system and are designed to stay secure without added weight. If water accumulates due to rainfall or snowmelt, it should drain through built-in systems or be manually removed to prevent damage.
Pros and Cons of Putting Water on Pool Covers
Benefits of Adding Water
- Improved stability – Keeps the cover tight and prevents flapping or billowing.
- Debris control – Prevents windblown dirt and leaves from sneaking underneath.
- Increased durability – Less movement means less wear and tear on the cover material and support hardware.
- Better water management – Water bags help guide rainwater toward designated drains, preventing pooling in unwanted areas.
Drawbacks of Standing Water
- Weight strain: Overfilling water bags can put undue stress on the cover and the support system.
- Mosquito breeding: Stagnant water on or around water tubes can attract mosquitoes, especially in warmer regions.
- Chemical interaction: If pool water bleeds onto the water bags, chemical corrosion can impact cover materials over time.
- Algae and mold development: Water left stagnant for too long may support algae or mold growth on the cover surface.
Best Practices for Adding Water to Pool Covers
If you decide to add water to your winter or mesh cover, following best practices ensures safety, performance, and longevity.
Use the Right Water Containers
When adding water, use specifically designed water bags or tubes made for pool covers. These are heavy-duty, UV-protected, and sized to fit appropriately across the cover. Homemade solutions or improper containers pose risks.
Fill Correctly
Each water bag should be filled to:
- Approximately ⅔ to ¾ full – This ensures weight without risk of bursting.
- Use clean water – Tap water is fine; avoid adding pool water which can corrode the plastic.
Strategic Placement
Place water bags evenly across the cover to:
- Distribute weight
- Prevent sagging
- Encourage water runoff
Regular Maintenance
During the off-season:
- Check water tubes for leaks or algae buildup.
- Drain and refill periodically to reduce contamination or staining.
- Ensure that your cover drainage system is functioning correctly.
Winter Climate Considerations
If you live in a region prone to freezing temperatures, it’s critical to address winter risks:
Freezing Water in Bags
Water inside the bags can freeze, causing expansion and container damage. To prevent this:
- Use antifreeze solutions in colder climates (only if safe for plastic bags).
- Ensure water bags are not filled to the brim.
- In extremely cold areas, some pool owners choose to leave water bags empty during harsh weather.
When NOT to Add Water to a Pool Cover
Depending on the type of cover you are using or your location, putting water on top may do more harm than good.
For Automatic Safety Covers
These covers are designed with tight tolerances and secure hardware that does not require extra weight. Adding water bags can interfere with the operating mechanism or stress the fastening points.
On Solar Covers
Solar covers float to capture solar radiation. Adding water to them causes them to sink and nullifies their function. Additionally, adding water may damage the plastic material due to overheating or stress.
When Water Could Contaminate the Cover
If your pool’s chemistry is unbalanced or has high chlorine levels, avoid placing cover water too near the pool edge to prevent chemical interaction that can degrade vinyl.
Expert Recommendations and Manufacturer Guidelines
Every decision related to pool cover use should include consulting the manufacturer’s instructions. Some companies:
- Mandate proper water bag placement
- Specify filling procedures
- Recommend cleaning and maintenance practices
It’s also important to follow guidelines set by organizations such as:
APSP (Association of Pool & Spa Professionals)
These industry standards encourage proper use of pool covers with water where applicable, especially for winter climates where wind and snow pose risks.
NSPI (National Spa & Pool Institute)
Recommends using clean water in cover tubes and maintaining even placement to prevent sagging and improve debris control.
How to Remove Water from Your Pool Cover Properly
When spring comes and it’s time to remove your winter cover, the method used to clear water off the cover is critical for safety, ease of use, and preservation of pool water chemistry.
Tools for Draining Water
Use a submersible pump with a long hose to remove standing water. Avoid manual scooping, which is time-consuming and potentially unsafe.
Cleaning and Storing the Cover
After removal:
- Drain all water from the bags and tubes
- Clean with fresh water and mild conditioner-free soap
- Dry completely before storing in a shaded, dry place
Storing wet or dirty covers can lead to mold, stains, and deterioration.
Conclusion: Should You Put Water on Top of Your Pool Cover?
The question “Do you put water on top of a pool cover?” has no single answer. It depends on various factors, including:
- Type of cover
- Climate conditions
- Pool location
- Manufacturer instructions
In summary:
Yes – Add Water If:
- You are using a mesh winter pool cover
- Your area experiences high wind or weather extremes
- Manufacturer guidelines recommend water bags
No – Do Not Add Water If:
- You have a solar cover or automatic safety cover
- You are in freezing conditions where water tubes may burst
- Water bags cause more harm than good (e.g., improper placement or excessive filling)
By understanding the purpose of your cover and your environmental conditions, you can confidently determine whether adding water is right for your specific situation. Proper care and attention to this detail will help ensure your pool remains clean, safe, and ready for the next swimming season.
Final Tips for Year-Round Pool Cover Maintenance
Whether you use a solid, mesh, or automatic cover, implementing maintenance habits ensures optimal performance:
- Check cover tension monthly in winter
- Never use bleach or strong cleaners on covers
- Reseal or patch tears immediately
- Protect covers from rodent or pest infestations during storage
Your pool is a significant investment of both time and money. By applying proper techniques and carefully deciding whether or not to add water on top of your pool cover, you safeguard that investment and keep your pool in excellent condition for years to come.
Why would someone put water on top of a pool cover?
Adding water to the top of a pool cover is a common practice aimed at protecting the pool and cover during harsh weather conditions, especially in winter. The weight of the water helps keep the cover securely in place, preventing it from being blown off by strong winds or damaged by shifting snow and ice. It also allows for proper drainage and prevents water from pooling in one spot, which can cause stress on the cover material and lead to premature wear.
In addition to stabilization, water serves a secondary function in managing the load caused by snow and ice accumulation. Pool covers designed to hold water often feature a built-in drainage system that accommodates this added weight. By maintaining water at the right level, typically 2–4 inches, the cover can evenly distribute pressure across the pool surface, reducing the risk of strain on the cover’s seams or the tensioning system. However, this method should only be used on covers specifically designed to support such loading.
What kind of pool covers can safely hold water?
Not all pool covers are suitable for holding water. Safety covers, typically made of heavy-duty mesh or solid vinyl, are designed to withstand the added weight when installed correctly. Mesh safety covers allow water to drain through, minimizing the amount of standing water, while some solid covers are built to hold water for pressure-balanced winterization. These covers are usually reinforced with grommets, webbing, and anchor systems that can handle the increased load.
On the other hand, standard winter tarps or lightweight floating covers are not made to carry water and should not be used for this purpose. Applying water to these types of covers can lead to sagging, tearing, or collapse into the pool, which may damage the pool walls or create safety hazards. Always check the manufacturer’s recommendations before adding water to your pool cover to ensure durability and proper performance throughout the off-season.
How much water should I put on a pool cover?
The ideal amount of water to place on a pool cover typically ranges between 2 to 4 inches. This depth provides enough weight to keep the cover secure without overloading the material or anchor system. Some types of covers require water bags or a special water-filled track, which further stabilizes the cover while enabling safe overflow drainage. Adjustments should be made depending on climate conditions, particularly in areas prone to heavy snowfall.
Too little water may not offer sufficient protection, while too much can stretch the cover material and overwhelm the safety system. Solid covers need special attention as standing water that exceeds recommended levels can cause sagging and potential damage. Monitoring throughout the season and maintaining appropriate water levels is crucial for safe and effective winter pool protection. If in doubt, consult the manufacturer’s guidelines or a pool professional for guidance specific to your cover type.
What happens if I add too much water to the cover?
Excess water on a pool cover can lead to significant problems, including undue stress on the cover material and anchoring system. When water levels exceed the recommended amount, the heavy weight can cause the cover to sag unevenly, stretch seams, and potentially tear. In solid covers, excessive water may also lead to collapse or cause water to spill into the pool, defeating the purpose of a winter cover and possibly contaminating the pool water.
Moreover, an overloaded cover could damage the pool deck or structure if anchor points are pulled loose. This may result in costly repairs and compromise pool safety. It’s essential to regularly inspect the cover and manage water levels with proper drainage tools or water tubes that help regulate weight. If a cover begins to sag or pool water accumulates in unexpected areas, corrective action should be taken immediately to avoid structural failure or water intrusion.
How do I drain water from the pool cover?
Draining water from a pool cover involves using manual or automated tools such as submersible pumps, water siphons, or water tubes that collect and release water periodically. These tools prevent water buildup while allowing some to remain for weight and protection. Most safety covers designed for water loading come with instructions on which method to use, whether it’s a small pump system or a simple siphon that removes excess without removing all of the stabilizing water.
Timing is key when draining water. It’s best to perform routine maintenance at regular intervals, especially after large snow melts or heavy rain events. Pool owners should always ensure that water drainage tools are functioning correctly and positioned ideally on the cover. A poorly placed pump or clogged siphon can lead to uneven water removal and create low points that trap debris or cause strain on the cover fabric. Monitoring conditions and staying proactive will help prolong the life of the cover and the pool itself.
Does putting water on the cover affect pool chemistry?
Water placed on top of a pool cover does not come into direct contact with the pool water below, so it does not directly affect the chemistry of the pool. However, improper drainage or cover failure could allow precipitation, melted snow, or debris-laden water to mix with the pool water, which would require additional maintenance. In some cases, if water bags or solid covers with standing water are used incorrectly, leaks or pressure imbalances can cause floating debris or contaminants to pass through to the pool.
To prevent these issues, regular checks of water levels and cover conditions are essential. Covers designed to hold water typically include barriers or seal systems that prevent overflow into the pool. Even so, it’s still advisable to maintain proper chemical balance and filtration before closing the pool for the winter, in case some water does enter. If water intrusion occurs, pool owners should test the chemistry early in the season and be prepared for slightly increased cleaning when the cover is removed for reopening.
When should I remove the water from the pool cover?
Water on a pool cover should generally be removed gradually as spring approaches and temperatures rise, signaling the beginning of the pool opening process. However, during the off-season, it may also be necessary to remove water when heavy rain or excessive melting adds more than the recommended amount. Monitoring the cover throughout the winter is important to ensure that water levels remain within safe limits and don’t become a liability.
When the time comes for full removal, start by using a pump or siphon to drain water before lifting the cover off. This prevents contaminated water from dripping into the pool and reduces the physical strain of removing a heavy, water-laden cover. After draining, clean the cover thoroughly and store it in a dry location until the next closing season. Proper maintenance of both the cover and water removal tools will ensure they are ready for future use and provide reliable protection year after year.