First, if the draining is done at the wrong time or under the wrong conditions, you can actually risk damaging your pool structure and liner. All the water from your pool needs to go somewhere when it's drained, and that usually means the ground.
An empty swimming pool can pop, or float out of the ground. This is due to possible hydrostatic pressure from unknown underground water.
The greatest danger you face when draining a pool is hydrostatic pressure. That's just a fancy term for the pressure of all of the groundwater around and under your pool pushing against your pool's walls and floors. Water is heavy, and hydrostatic pressure can be significant.
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.
As noted, typical maintenance or winterizing your pool shouldn't require you to completely drain the water. You risk damaging your pool liner and the structure of your above ground pool.
Inground pools made of concrete or gunite are susceptible to popping out of the ground if drainage is not done properly. If there has been a surplus of rain recently or your pool is located in a wet area, it is best not to try and drain the pool yourself at all.
Pool industry experts recommend you drain your pool and refill it every five to seven years. No two pools are alike, so there is no set number at which you must drain your pool.
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.
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.
How long it will take to drain your pool will depend on the size of your pool, and how many gallons per minute the pump can move. But you're probably looking at somewhere between 8 and 14 hours for your pool to empty.
Should I drain my pool to get rid of algae? Yes, you can because it saves time and money, but only if you do it properly. Use the main drain in your pool and drain water through the filter pump. Or rent or borrow the pump, place the hose down the street or storm drain, and drain.
Generally, pool water needs to be replaced once every five to seven years. This should be done during mild weather so that your pool surface is not at risk from strong sunlight and heat. Your pool maintenance company can recommend when it is time to drain your pool.
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.
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.
Much of this rain water penetrates into the ground, raising the inground water table, which creates a lot of hydrostatic pressure pushing up on the pool. After the water table raises enough, the pool may float or pop up out of the ground.
You'll need to keep draining water off the cover with a pump or siphon to protect it from damage. Important: Never drain an above ground pool completely when winterizing. Your vinyl liner can dry out, shortening its life considerably.
If you have an above-ground pool with a vinyl pool liner, drain the pool to about 1 inch below the bottom of the skimmer mouth. 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.
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.
A faster draining is preferred, to allow you to hose off the walls while it drains, to prevent dried on dead algae from baking in the sun. Use enough discharge and direct the water far enough away so that it's not coming to rest under the pool.
Use a pool brush to vigorously scrub any pool surfaces covered in algae, including the walls, floors, and steps. Apply a green algaecide according to the directions on the label. Let the water circulate for 24 hours, then brush the pool surfaces again. Vacuum or backwash to remove any remaining dead algae.