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How Long Does It Take to Fill a Pool with a Garden Hose? | A Simple Formula

Knowing how long it takes to fill a pool is important. Can you just throw in a hose and let it run overnight, or would it fill too quickly? I’ve owned a pool at several properties over the years, and so I can give you a definitive answer.

With a standard size 1/2 inch garden hose, it takes about 9 hours to fill a 5000-gallon pool. To figure the time needed yourself, multiply the number of gallons your pool holds by .0018. The volume of water a standard hose can deliver per minute is approximately 9 gallons or 540 gallons in an hour.

Now that you know the approximate time, let’s get a bit more specific. The rest of the article will tell you how to figure out a more exact fill time for your own pool. We will also talk about the exact cost and whether there are any other options available to fill it.

How Long Does It Take to Fill a Pool with a Garden Hose?

Water Hose Filling up an Empty Pool

It can take several hours to fill your pool with a garden hose. This depends on the amount of water your hose can deliver per minute.

The amount of water your hose can deliver per minute also depends on the hose’s size, meaning its diameter and length, and the water pressure.

No surprises here; you can reduce the amount of time in filling up your pool by using a larger hose.

Water Pressure and How it Affects Filling Speed

The rate at which water is delivered to your pool depends on the water pressure. High water pressure can mean a faster water delivery time compared to low water pressure.

The amount of time needed to fill up your swimming pool mostly depends on your swimming pool’s water pressure and volume. It is important to know how many gallons per hour are produced by your faucet and the water volume capacity that your swimming pool holds.

How to Determine the Water Pressure of Your Hose

You can easily determine water pressure from a hose using the following simple method.

Let us assume that you have a 5-gallon bucket. With the hose, you will use to fill your swimming pool, start filling your bucket with water. I recommend making use of a stopwatch to time how long it will take for the 5-gallon bucket to fill up.

Here is a simple formula to determine your water pressure or gallons per hour (GPH):

Let Y be the number of seconds it takes to fill up 1 gallon of water. So, in our example:

  • Y = No. of seconds to fill up a 5-gallon Jug /5
  • GPH = (60/Y) x 60
  • Where 60/Y = gallons per minute

Using this formula, let’s say it took 50 seconds to fill up a 5-gallon jug, it will take 10 seconds to fill up a 1-gallon jug since 50/5 = 10.

The GPH is then (60/10) x 60 = 6 x 60 = 360. The water hose will deliver 360 gallons of water per hour.

Assuming that your pool capacity is 20,000 gallons, it will take 20,000/360 or 55.55 hours to fill up your swimming pool.

Related Can You Drink Pool or Hot Tub Water in an Emergency?

How to Determine the Volume of Water a Pool Holds

To determine the volume of water a pool holds, it is necessary to know your swimming pool dimensions. Here are some formulas that will help you determine the water volume capacity of your pool.

If you have a circular or an oval pool, consider using these formulas.

For a circular pool:

  • Water volume capacity = pool diameter x pool diameter x average pool depth in feet x 5.9

For an oval pool:

  • Water volume capacity = Length of longest distance x length of the shortest distance x average pool depth x 5.9.

Let us consider these examples:

  • If you have a circular pool with a diameter of 24 feet and an average depth of 5 feet, then your pool’s water volume capacity is 24 x 24 x 5 x 5.9 = 16,992 gallons.
  • If you have an oval pool, which measures 30 feet long at the longest point and 20 feet at the shortest point, and with an average depth of 5 feet, then the water volume capacity of your oval pool is 30 x 20 x 5 x 5.9 = 17,700 gallons.

For a rectangular or square pool, use the following formula:

  • Water volume capacity = length x width x average depth x 7.5

Therefore, if your pool is 20 feet long and 10 feet wide and 6 feet in the deep end, and 4 feet in the shallow end, its water volume capacity is 20 x 10 x 5 x 7.5 = 7,500 gallons.

Filling Speeds of Different Common Sized Pools

Here is a chart that can help you determine the time your swimming pool can fill up based on water pressure or gallons per hour.

Water CapacityGPHFill Time
5,000 Gallons42011.9 hrs
10,000 Gallons42023.8
15,000 Gallons42035.7
20,000 Gallons42047.6
25,000 Gallons42059.5

Now that you know the time it will take for your swimming pool to fill up, you can then relax without worrying that your swimming pool is overflowing.

Pro Tip: The filling process may slow down if the water is being used in your home at the same time that your swimming pool is being filled. Avoid using the water so that the water pressure will not drop. This will cause a longer fill time.

How Much Does It Cost to Fill a Pool with Water?

Swimming Pool Shaped Like a Dollar Sign

On average, most households use 12,000 gallons of water per month. If your pool’s water volume capacity is between 15,000 to 30,000 gallons, you can expect your water bill to approximately double when you fill your pool with water from a hose.

If you want to get a more accurate cost of filling up your pool, contact your local water company to get an idea of how much the cost of water per gallon is. Prices of water vary for every city and state, so it is not possible to provide the cost of filling up your pool. If you can determine the price per gallon in your area, then you simply multiply this amount by the water volume capacity of your pool in gallons, then you will be able to estimate the cost.

Is Water Delivery a Good Option?

9,000 gallons will typically cost about $375 when delivered locally but will vary based on your region.

Water delivery is a good option since your pool can be filled with high-quality water in a shorter amount of time. You don’t even have to do anything. And while they are filling up your pool, you can check for any potential problems like leaks and other issues. These things can be overlooked when filling with a hose because no one watches it. It will be too late before issues are detected.

Bottom Line: A 25,000 gallons pool can take you 40 to 60 hours to fill using a water hose. If you use water delivery services, they can deliver pool water in very few trips. Some trucks can carry up to 9,000 gallons of water. It will definitely cost you more than using a water hose. But you are paying for convenience.

How to Fill a Pool Without a Hose

You can fill your pool through other means aside from using your garden hose. You can use truck delivery services and have water transported to you, you can use well water, or you can ask your local fire department if they provide this kind of service.

So, which is the most practical for your pool, your budget, and your time? Let’s check out the differences among these water sources.

Well Water

One of the options you can have in filling up your pool is by using well water. One of the advantages of using well water is that it is absolutely free, making it an attractive option and by far the cheapest source of pool water. However, other things need to be considered.

  • One of the main issues with using well water is the water quality. Well water has a distinct odor. It smells of sulfur.
  • Well water may also contain iron, copper, and hydrogen sulfide.

This is why it is important to check the water content before using it. Despite well water being free, there is a risk of having high levels of elements that you need to treat with expensive chemicals.

  • Another thing with well water is the issue with the pump. Pumping water into a swimming pool can overwork your pump, especially if you have a big pool. It will wear your pump a lot. The important thing if you are going to use well water is to determine how long you are going to run it. Also, consider how deep your well goes if you don’t want to run your well dry.

If Unsure, Have it Tested

So, if you want to use well water, it is crucial to have your water quality tested and consider the longevity of your well’s pump.

Delivery is a Solid Option

The most convenient and fastest way of filling up your pool is by having water delivered. These delivery services use a hose that is very large in diameter so that your pool fills faster.

Although transporting water is the most expensive, you are paying for convenience.

Large Water Delivery Truck

Final Thoughts

Personally, I have always just used my own hose to fill a pool. While it can take a full day or longer and often triple my water bill for the month, I find it’s the most convenient and cheapest way to go.

Once you have your pool filled, let me know the type of hose you used, the size of the pool, and how long it took to fill in the comments below. I’d love to hear how it went and if your calculations turned out exactly as planned.

I hope this article has been helpful. Thanks for reading!

For more, check out What Is an Expandable Garden Hose and When to Choose One?