How Long to Fill a Pool With a Hose? (Calculator & Guide)

How Long Until Splashdown? Filling Your Pool with a Garden Hose

Getting a new pool is exciting, but before you can jump in, there’s one big question on every new owner’s mind: “How long will this actually take to fill?” For most people, the trusty garden hose is the tool for the job. It’s easy and accessible, but the fill time can feel like a mystery.

The good news is that you don’t have to guess. The time it takes to fill your pool depends on two simple things: the size of your pool and the speed of your water flow. This guide will walk you through exactly how to figure it out, estimate the cost, and get your pool ready for its first swim. If this is part of a complete drain and refill, make sure you know how to prepare your pool for the refill first.

The Key Number: Gallons Per Minute (GPM) from Your Hose

The most important number you need to know is your hose’s Gallons Per Minute (GPM). In the United States, the U.S. Geological Survey (USGS) confirms that a standard garden hose can deliver water at a rate of 5 to 12 GPM. This wide range depends heavily on your home’s water pressure and the hose’s diameter.

For international context, government sources like the Northern Territory Government in Australia note that a typical water supply to a house is around 0.25 litres per second. This converts to 15 litres per minute (LPM), or just under 4 gallons per minute (GPM). This difference highlights why testing your own flow rate is so important, as it can vary significantly by location.

The best way to find your specific number is with a quick test, which you can do using the “Bucket Test Calculator” in Step 2 above.

The Calculation: How to Figure Out Your Pool’s Fill Time

Once you know your hose’s GPM and your pool’s total volume in gallons, the math is straightforward.

The Formula:
Pool Volume (in Gallons) / Your Hose GPM = Total Minutes to Fill

To make it easier, you can convert the total minutes into hours:
Total Minutes / 60 = Total Hours to Fill

Estimated Pool Fill Times (Chart)

Here’s a handy chart showing estimated fill times for common pool sizes based on different hose flow rates.

As you can see, filling a large 30,000-gallon pool can take several days with a single hose!

Real-World Factors That Change Fill Time

• Water Pressure: Higher household water pressure means a higher GPM and a faster fill.
• Hose Diameter and Length: A wider hose, like a 3/4-inch model, allows more water through than a standard 5/8-inch hose. Choosing the best hose for filling your pool can make a noticeable difference.
• Faucets and Spigots: The outdoor spigot you connect to can also have its own flow rate. Similar to how you can remove flow restrictors from faucets to improve pressure, ensuring your spigot is fully open and clear of blockages is key.
• Obstructions: Kinks or knots in your hose are the most common culprits for slowing down water flow. Make sure the hose is laid out straight. If you run into issues, see our guide on solving common problems when filling a pool.

Speeding Up the Process: Faster Ways to Fill Your Pool

If waiting isn’t for you, explore these tips to fill your pool faster.

• Using Multiple Hoses: This is the easiest trick in the book. Yes, your pool will fill much faster with two hoses. If you have two outdoor spigots, running two hoses at once will cut your fill time roughly in half, as long as your home’s water pressure can support both.
• High-Volume Pumps: For very large pools, you could rent a high-volume water pump. This is a faster but more complex and expensive option.
• Water Delivery Services: The fastest method is to hire a water delivery service. They use large tanker trucks to fill a pool in just a few hours. This and other methods are covered in our guide to alternatives to filling your pool with a garden hose.

The Cost of Filling: Beyond Just Time

Time isn’t the only consideration; there’s also the cost of the water. This is a crucial related question many people have: “How much does it cost to fill a pool?“

The cost depends entirely on your local water rates. You can find this information on your utility bill, usually listed as a price per gallon or per 1,000 gallons.

The Cost Formula:
Pool Volume (in Gallons) * Your Local Cost Per Gallon = Total Fill Cost

For example, if your city charges $0.004 per gallon and you have a 10,000-gallon pool, your cost would be $40.

Practical Tips for Filling Your Pool Safely and Effectively

• Protect Your Liner: Don’t just toss the hose into the pool. The force of the water can damage vinyl liners or leave marks on plaster. Place a soft cloth or towel directly under the hose end to soften the stream.
• Monitor the Water Level: It’s important not to overfill your pool. If the water level goes above the skimmer opening, the skimmer can’t do its job of cleaning the surface. Set alarms on your phone to check the progress regularly. Once it’s full, you’ll need to know how to maintain your pool’s water level correctly.
• Can You Fill a Pool Overnight? Yes, you absolutely can fill a pool overnight, and it’s a common practice for larger pools. Just be sure to monitor it carefully to prevent overfilling. It’s a good idea to check it before you go to bed and first thing in the morning.
• Choosing Your Water Source:
  • Can you fill a pool with tap water? Yes, this is the most common method and generally the easiest.
  • Can I fill a pool with well water? Yes, but be cautious. Well water can be high in minerals like iron and copper, which can stain your pool’s surface. It’s a good idea to use a hose filter or add a metal sequestrant chemical as the pool fills.

After the Fill: Getting Your Pool Ready

• What should I put in my pool when I first fill it up? The first thing you should do is test the water with a good quality test kit. You’ll need to check the pH, total alkalinity, calcium hardness, and chlorine levels.
• Balance the Water: Based on your test results, you will add chemicals to get everything in the proper range. This usually involves adjusting the alkalinity first, then the pH.
• Does hose water raise pH in a pool? It often can. Municipal tap water tends to have a higher pH. It’s very common to need to add a pH decreaser (or muriatic acid) to your new pool water.
• Sanitize: Once the water is balanced, it’s time to add chlorine to sanitize it and prevent algae and bacteria from growing.
• Circulate: Run your pool pump and filter continuously for the first 24-48 hours to mix the chemicals and clear the water.

Frequently Asked Questions (FAQ)