Filling a swimming pool can take a bit more time than people might expect.
Average-sized swimming pools In the United States take around 12–24 hours to fill. Various factors affect the filling time, like the pool’s volume and water pressure. For this reason, it is difficult to give an answer based on the size of the pool only.
If you have your own pool, a measuring tape, and a calculator, you can easily determine a fairly accurate filling time for your pool.
Let’s get into that step-by-step.
Factors Affecting Pool Filling Time: 1000, 5000, 6000 and 10000 gallons.
The following four factors are the main deciding ones when it comes to filling time. Once you take all of them into consideration, you’ll have a reasonably accurate pool-filling time.
Dimensions of the Pool
Swimming pools exist for different purposes, which often controls their size. For example, an Olympic pool is 164 feet long and 82 feet wide.
On the other hand, family and home swimming pools are often much smaller. Such pools’ average dimensions are 10 x 20 ft or 20 x 40 ft.
Keep in mind that we’re currently talking about rectangular pools only. Pools could also be oval, square, or even triangle-shaped.
Depth of the Pool
The depth of the pool is another filling time factor. For example, two rectangular pools of identical lengths and widths will require different water volumes and times to fill if their depth is different.
Keep in mind that many pools have variable depths as well. In that case, you’ll need to measure the average depth of your pool to get a more accurate result when calculating the filling time.
Flow Rate / Water Pressure
The water flow or pressure of your water hose will determine how fast your pool fills. For example, two identical pools will fill at different speeds if the hoses have different water flow speeds. You can add a water pump to speed things up if needed.
The Number of Water Sources
Two hoses will fill a pool in much less time than one pool. Of course, having water flowing through two hoses simultaneously will reduce the water flow through each of them to some extent.
However, the total filling time will still be faster.
Calculating a Swimming Pool Filling Time
To calculate the filling time of your swimming pool, you’ll need to know a few things; those are:
-The length of your pool
-The width of your pool
-The depth of your pool
-The total volume of your pool
-The average water flow of your hose
-Measuring the length, width, and depth of your pool is easy. All you need is a measuring tape.
The tricky part is calculating the volume of the pool, how fast your hose is, and how many gallons your pool requires. But we’ll make that easy for you too.
So let’s begin with a 20 x 40 ft pool.
A 20 x 40 ft pool will require around 21,000 gallons of water if its depth is 3.5 ft. If the depth is 4, 4.5, or 5 feet, the required gallons will be 24,000, 27,000, and 30,000, respectively.
Let’s assume that your water flow can fill a 1-gallon bucket in 7 seconds. We’ll also assume that your 20 x 40 swimming pool is 4.5 ft deep. That pool needs 27,000 gallons of water.
Since your water flow can fill 1 gallon in 7 seconds, it will need 189,000 seconds (7 x 27,000) to fill the pool. 189,000 seconds is 3,150 minutes which translates to 52.5 hours.
If your pool is 20 x 40 ft, then it’s a good coincidence. However, if it’s not, we’ll show you how to calculate the whole thing from scratch.
Calculating the Volume of Your Pool
The first thing you need to do is to calculate the volume of the swimming pool. We’ll standardize our units to be imperial. So we’ll be using feet, cubic feet, and gallons.
Every cubic foot contains 7.5 gallons of water. So, once you find out the volume of your pool in cubic feet, you’ll need to multiply that by 7.5 to get the number of gallons required to fill your swimming pool.
So, let’s assume that your swimming pool is 30 feet long and 15 feet wide. Also, the depth of your pool is 5.5 feet.
So, the volume of your pool in cubic feet will be 30 x 15 x 5.5 = 2475 cubic feet.
Calculate the Gallons Required to Fill Your Pool
Now, multiply that by 7.5, and you’ll get the required gallons to fill your pool. So in this example, the answer will be 18,562.5 gallons.
Calculate the Flow of Water Through Your Hose
You’ll need a stopwatch and a bucket of a known size. To make this as easy as possible, get a 1-gallon bucket.
Turn on the stopwatch and start your water hose. Once the bucket fills, stop the watch and see how many seconds it took.
For practical application, we’ll assume you’re using two hoses, not just one. Working together, they managed to fill that 1-gallon bucket in 4 seconds.
How Long Does It Take To Fill a Pool
Now that you have your pool’s required gallons and the speed of how your water hoses will fill 1 gallon, you’ll need to multiply the pool’s gallons by the time of the 1-gallon filling speed.
In our example, we’ll multiply 18,562.5 by 4, which gives us 74,250 seconds.
Divide that by 60 to get 1,237.5 seconds. Then, divide again by 60 to get 20.6 hours.
So, with a water flow of 4 seconds per gallon, you’ll fill a 5.5 ft deep 30 x 15 pool in 20.6 hours.
You can refer to this pool capacity calculator if you want a much faster way of doing the whole
thing. For example, you can try inputting our example pool’s dimensions in that calculator, and you’ll get the same results.
The calculator will ask for the gallons per minute, and since we get 1 gallon per 4 seconds, a minute will fill 15 gallons.
So, How long does it take to fill a pool? Roughly anywhere between 12–24 hours if you have a couple or more hoses working on it.
If you want a better result than that 12-hour window, you need to determine your pool’s volume and your hose’s water pressure.
You can also use a strong pump to fill the pool faster if you have a nearby water source.
Once you do that, apply the calculations we did or simply use the online calculator.