Is Your Pool Water Evaporating or Leaking? The 24-Hour Bucket Test

It’s a classic July scenario: the sun is blazing, the family is swimming every day, and suddenly you notice the water level looks a little lower than it did last week.

Instantly, panic sets in. Do I have a leak? Am I going to have to dig up my deck? How much is this going to cost?

Before you stress, take a deep breath. July brings peak temperatures and low humidity, which creates the perfect storm for rapid evaporation. In fact, a typical pool can easily lose up to 1/4 inch (about 6 mm) of water per day just from the heat and wind.

But how do you know if your pool is just "sweating" in the July heat or if there’s an actual tear in your liner or a plumbing leak? Enter The 24-Hour Bucket Test. It’s a simple, foolproof DIY trick that costs next to nothing. Here is how to do it.

How to Run the Bucket Test

To get the most accurate results, choose a 24-hour window when no one will be swimming, and turn off any automatic water autofillers if you have them.

Step 1: Grab a Bucket

Find a standard 5-gallon plastic bucket. Fill it with pool water until the water inside the bucket is about 3–5 inches from the top.

Step 2: Set the Stage

Place the bucket on the first or second step of your pool, submerging the bottom of the bucket in the pool water. (This ensures the water inside the bucket stays the exact same temperature as the pool water, mimicking the same evaporation rate).

Step 3: Mark the Levels

• Inside the bucket: Use a waterproof marker or a piece of electrical tape to mark the exact water level inside the bucket.
• Outside the bucket: Mark the pool's water level on the outside of the bucket.

Step 4: Wait 24 Hours

Leave the bucket alone for exactly 24 hours. Keep the pool pump running as you normally would.

Analyzing Your Results

After 24 hours, grab a tape measure and look closely at your marks.

Scenario A: The levels dropped equally.

If the water level inside the bucket and the pool water level outside the bucket dropped by the exact same amount, congratulations! You do not have a leak. What you are experiencing is purely July evaporation.

💡 Tip to fight evaporation: Consider using a solar cover at night to trap heat and prevent the dry night air from stealing your pool water.

Scenario B: The pool level dropped more than the bucket level.

If the pool water level on the outside of the bucket went down significantly more than the water level inside the bucket, you likely have a leak.

What to Do If You Have a Leak

Don't panic! Finding a leak early prevents structural damage and saves you money on water bills.

First, do a quick visual inspection. Check around your pool equipment pad for any obvious puddles, drips, or wet soil. Look closely at the pool liner for any visible tears, particularly around the skimmer, return jets, or steps.

Next, give Main Street Pools a call. Our expert team can help diagnose the issue, walk you through your options, or assist with professional service and vinyl liner replacements to get your pool tight, right, and ready for the rest of summer.