Understanding the Weight of a Swimming Pool
When a swimming pool is filled with water, it becomes incredibly heavy, making it nearly impossible for a person to lift or relocate it unless the water has been completely drained. Even small pools, such as kiddie or toddler-sized pools, present a significant challenge if someone attempts to move them after they have been filled. The weight of a swimming pool is primarily determined by the amount of water it contains. Specifically, one gallon of water weighs approximately 8.34 pounds. If you have an average-sized swimming pool that holds 15,000 gallons of water, the total weight of the water alone would be about 125,100 pounds. To calculate this, simply multiply the number of gallons of water by 8.34. Keep in mind that this figure reflects only the weight of the water contained within the pool; it does not account for the weight of the pool liner, support poles, ladders, pumps, and other associated components.
| Gallons Of Water | Weight Of Water |
| 1,000 Gallons (Miniature Pool Or Hot Tub) |
8,340 Pounds |
| 2,500 Gallons | 20,850 Pounds |
| 5,000 Gallons | 41,700 Pounds |
| 10,000 Gallons | 83,400 Pounds |
| 15,000 Gallons | 125,100 Pounds |
| 20,000 Gallons | 166,800 Pounds |
| 25,000 Gallons | 208,500 Pounds |
Importance of Level Ground for Pool Installation
The substantial weight of water is a critical factor to consider when filling an above-ground swimming pool. It’s essential that the ground is level before setting up any above-ground pool. In some cases, it may be necessary to allow the ground to settle after significant landscaping work, which could involve the removal of trees and stumps or the addition of large quantities of soil. The immense weight of water pressing down on the freshly disturbed soil can lead to significant issues, potentially damaging the pool’s liner and walls. If the ground shifts too much, it can pose a risk of injury to swimmers if the pool collapses due to undue stress.
How Level Should an Above-Ground Pool Be?
Given the weight of the water, ensuring that the ground is stable and level is paramount before setting up any above-ground swimming pool. This is true for pools of all sizes, with the possible exception of small inflatable baby pools that are typically drained after use. For instance, a small 12-foot round swimming pool with a height of 36 inches would require approximately 2,548 gallons of water to fill completely. This means that a filled 12-foot round pool would weigh over 20,000 pounds, and without a precisely level base, the water will not distribute evenly. As water fills the pool, it can create uneven pressure on the walls, leading to an unsafe and visually unappealing swimming pool.
How Level Does Your Water Need to Be?
Achieving a perfectly level pool is crucial during installation. This task can be challenging to accomplish with the naked eye. One effective method is to use long 2x4s along with a level to ensure accuracy. If the pool is not level and you notice discrepancies after filling it halfway, it may be necessary to drain it and start over. INYO Pools recommends draining the pool if the water level is more than 3 inches off after filling, as this can create excessive pressure on one side of the pool walls, leading to potential structural failures and safety hazards.
| 1/4″ Off Level | Great! Your pool’s water is level enough. |
| 1/2″ Off Level | Good! Your pool’s water is level enough. |
| 1″ Off Level | Still OK. It may start to be more noticeable from the outside of the pool. |
| 2″ Off Level | Fair. Your pool should be fine, but it will be noticeable to guests and won’t look as aesthetically pleasing as a perfectly level swimming pool. |
| 2.5″ Off Level | Anything above 2.5 to 3 inches off, I would highly recommend draining, re-leveling, and refilling. Especially anything over 3 inches poses a risk of injury and damage to your swimming pool. |
Conclusion
The weight of water can be staggering, as each cubic foot contains approximately 7.48 gallons. Each cubic foot of water weighs around 62.38 pounds, and when considering the weight against the walls of the pool, it is vital to ensure that the structure is level to avoid undue pressure. Even a level swimming pool experiences significant weight against its walls, and any additional pressure from an unlevel installation can be detrimental. Before installing your swimming pool, or if you already have an above-ground pool that is not level, it is essential to address these issues for the safety of all users and to prolong the lifespan of your pool.