Never completely drain a fiberglass or in-ground vinyl liner pool; doing so can damage the integrity of the pool surface or liner in the form of bowing or cracking. The best practice is to partially drain these types of pools. Always complete partial drains by 1/3 of the water at a time.
An empty swimming pool can pop, or float out of the ground. This is due to possible hydrostatic pressure from unknown underground water.
When one drains the pool and there happens to be water under the shell (like in the rainy spring when people want to clean up the pool) the entire pool shell can heave. This is because the water under the pool creates an upward hydrostatic force (through buoyancy) and the pool is lifted out of the ground.
It's acceptable to drain the pool a few more inches below that if you live in an area that gets heavy precipitation during the winter months. Some pool professionals even suggest draining the water to as much as 6 inches below the skimmer — about the level of the bottom of the pool's return jet.
Once water is removed (and subsequently, the interior hydrostatic pressure), if there's an influx of groundwater, it will push the pool up and out of place. As a general rule, you shouldn't keep any pool empty for longer than it needs to be. Get the work done that you needed to do and refill it as soon as possible.
If ground water is not a problem a pool can be left empty for weeks or even months as long the hydrostatic relief in the bottom of the pool is open and functioning. If the time frame of the pool being empty gets into freezing weather there is real risk of freeze-thaw damage to surface of the pool.
The weight of ice or snow are common culprits of pool collapse. Draining your pool too much. An older inground pool may not be able to withstand the weight of dirt against it once it is empty or if the water levels are too low. Groundwater can also push against the pool walls and cause it to collapse.
Modern concrete pools can usually stand being drained for as long as needed, but there'll still be a risk of popping if the ground water level is high. Fibreglass pools are less resilient. The floor may come loose and float to the top when refilled, even after a short period.
An empty pool (or as little as 1/4 filled) and an exposed liner on a hot day can cause the liner to shrink from the heat and deem the liner useless. An empty pool is also susceptible to collapse. Especially, in high winds and/or bad weather.
Close the pool for winter – but don't drain it.
In winter, the water in your pool is still your friend. Especially when properly winterized, it helps to protect the pool liner, keep it clean and prevent unnecessary damage from debris, harsh weather and other factors.
Wrapping Up. Rest assured that popped pools do not happen very often. But if they do, they can be costly to repair. While it is possible to perform that repair, it is best to avoid a floating pool in the first place.
Flooding Your Grass Is Not A Good Idea
The problem with draining your pool in the yard, if permitted by your local water regulatory laws, is that it will quickly reach its saturation level and increase the risk of flooding your lawn, drowning the roots of your grass, and attracting mosquitoes.
The average outdoor spigot on a home can produce up to 12 gallons per minute. A small pool can be filled in a few hours, while a large one can take 14 hours.
Pool water should never be drained to the street or the storm drain. Storm drains in the Bay Area typically run into local creeks, rivers and the bays.
The answer is always NO. Above ground pools need the weight of the water in them to provide an optimal level of stability. Without water supporting the wall you run the risk of the pool wall coming out of the track. Also without water in the pool the liner can shrink and no longer fit your pool.
Depending on the type of material that your pool is made out of, exposure to the elements may damage it. Because of this, the best time to drain your pool is when the weather is mild. If the temperature will be over 85 degrees at any point in the process, it is best to postpone.
Whether you drained yours partially or completely, the rules for refilling an above-ground pool are the same. At the end of the day, a pool is designed to be full of water.
It typically costs $500 to $700 to drain and clean a pool and usually takes several days. Since it's more expensive, a pool company will try other common treatments to clean the pool first.
Big disclaimer: only authorized fiberglass pool professionals should drain a pool. Never drain a pool without professional assistance. For most (if not all) pool manufacturers, an authorized dealer must drain the pool, or you may void your warranty.
A sinkhole can occur whether you have an inground pool or an above-ground pool. A pool that is allowed to leak into the foundation underneath can lead to a very large, very dangerous sinkhole. In fact, leaking water is the main cause of a sinkhole. Sinkholes start developing a long time before they actually appear.