How to Measure Water to Fill a Pool

Measuring water to fill a pool is a common pool owner task.

Pool owners often need to know the volume of their swimming pool for initially filling the pool and adding chemicals. Once you calculate the formula, you should write it down and keep the information where you store pool chemicals for easy reference. The basic formula for measuring the water to fill a pool is length in feet times width times the average depth of the pool. This gives you the cubic feet which you multiply by 7.5, for rectangular pools to get gallons. Another important measurement is determining how long it will take to fill the pool using a garden hose.

Things You'll Need

• Tape measure
• Calculator
• 5-gallon bucket
• Garden hose
• Stopwatch

Instructions

Measuring Pool Volume

1. Measure the pool's length by placing the tape measure at the two points farthest points along the pool. Measure the width by placing the tape measure at the two farthest points across the pool. For a round pool, simply measure the diameter. Ask a friend to help you with this part of the project.

2. Add the feet from the shallow and deep end of the pool and divide by two to find the average depth. For example, a pool with a 3 foot shallow end and 9 foot deep end has an average depth of 6 feet.

3. Multiply the pool's length by the width by the average depth in feet. This figure represents the pool's total water volume in cubic feet. Convert this to gallons by multiplying the cubic feet figure by 5.9 for round or ovals pools or 7.5 for square, rectangular or custom form pools.

Fill-up Time

1. Place a 5-gallon bucket on the ground. Place a garden hose in the bucket and turn on the faucet.

2. Time how long the bucket takes to fill up using a stopwatch.

3. Divide 60 minutes by the time (in minutes) it took to fill the bucket and multiply by five, which represents the bucket size in gallons. For example, a 90 second fill-up time means your pool will fill at a rate of 200 gallons an hour.

4. Divide the figure from Section 1, Step 3 ( gallons) by the figure from Section 2 Step 3 (gallons per hour) to determine how many hours it will take to fill your swimming pool.

Tips & Warnings

• For round pools multiply the diameter by the diameter by depth by 5.9. For oval pools mutiply length by breadth by depth by 5.9.

• Custom form pools --- such as T or L shape --- may require you to separate the pool into measurable squares to calculate the water volume.

References

• "The Ultimate Pool Maintenance Manual: Spas, Pools, Hot Tubs, Rockscapes and Other Water Features, 2nd Edition"; Terry Tamminen; 2000