How To Find a Leak In Your Pool

Finding a leak in your pool is never a good sign. Pool leaks are a common issue and can often be tough to solve for many pool owners. With the proper knowledge, however, you can locate and fix them quickly.

The thing about pool leaks is that they can occur practically anywhere inside and outside of the pool. The most significant challenge is often locating the leak. I will give you some strategies for finding leaks and discovering if you have a leak or if the problem is just evaporation.


Main Takeaways

  • The two main ways to find a leak in a pool are by filling and submerging a bucket or using food coloring to locate the source of the leak.
  • If your pool water level is dropping at an unusual rate, you may have a leak. This is typically the most telltale sign of a leak.
  • If you have a tear in your vinyl liner, you’ll need a vinyl patch kit to repair the tear. If you have a crack in a concrete pool, you’ll need to repair the pool plaster.

How to Tell If Your Pool is Leaking

The most obvious sign of a leaking pool is water loss. However, other symptoms can also tell you that you’ve had a pool leak. Watch out for the following signs.

The Water Level Goes Down

A pool leak will lead to a drop in the water level. However, a change in water levels does not always mean that your pool is leaking. Pools lose water naturally through evaporation.

You have to figure out if the change in pool water levels is due to a leak or simple evaporation. Evaporation rates vary from one place to another due to differences in climate. Even in the same place, rates can vary due to water temperature, humidity, and wind.

You should know the average evaporation rate in your area by looking at current weather data. If you’re getting far more water loss than evaporation averages, then there is a high chance you’re looking at a pool leak.

You Have Cracks In Your Tiles or Falling Tiles

When a pool leaks, the surrounding ground becomes unstable due to all the excess water. As a result, the tiles surrounding the pool may crack or begin to move. Finding gaps and cracks might mean a leak has been going on for a while, and the water has seeped farther outward.

You Have Wet Spots In Your Yards

Wet areas are yet another tell-tale sign that you might have leaks. Uneven grass or muddy spots near the pool may indicate a pool leak. As the water moves underground, it erodes the soil and causes the landscaping above to shift or even sink.

Your Water Bill Is Higher Than Normal

An automatic pool filling device can hide a pool leak by ensuring the pool stays full. However, if the device gets triggered to start more frequently than usual, your water bills will rise. Higher water bills, without another explanation, could be a sign of a leak.

There Is Water Under Equipment

Signs of severe corrosion on pipes and pumps near the pool or stagnant water (despite no recent rainfall) typically mean your pool is leaking.

Dirt or Air Passing Into The Pool Through a Pump

A leak will make it easier for air and dirt to get pulled into the pool’s plumbing. The underwater air release often comes with an inexplicable gurgling noise. It is a sure sign of a leak.

Algae In Your Pool

Algae growth comes when new and untreated water gets added to a leaking pool. This untreated water leads to fluctuations in chemical levels that might encourage algae development. Rather than continue treating the water, you can consider looking for a leak.

How to Locate The Leak In Your Pool

There are two main ways to detect a pool leak. The most popular one is known as the bucket method, and the other involves food coloring.

Method 1: Use a Bucket To Determine There is a Leak

The bucket test is the simplest option and is the best way to check if there is a leak in the first place.

  1. Grab a 5-gallon bucket.
  2. Submerge the bucket in the water and place it on the second step of the pool.
  3. Fill the bucket so that the line in the water matches the waterline of the pool.
  4. Mark the waterline of the bucket using a piece of duct tape.
  5. Turn off the pool pump.
  6. Wait around 24 hours.
  7. Compare the waterlines. If the water in the bucket is higher than the pool, then there is likely a leak; if they are still the same, the pool water is going down due to evaporation.

This method helps to eliminate the possibility that the pool’s water level is changing due to evaporation.

Method 2: Use Food Coloring to Locate the Location of the Leak

If you’ve got a strong suspicion that your pool has a leak, the food coloring method is the best way to pinpoint it.

  1. Grab some food coloring.
  2. Turn the pump off to ensure the water is as still as possible.
  3. Check the areas around the pool for wetness. If there are unusually wet areas, there may be a leak there.
  4. Squeeze a small amount of food dye near the area where you suspect the leak to be.
  5. If you are unsure of where the leak is, go around to different areas of the pool and squeeze some dye near the wall, or near fittings, such as the return, drain, lights, and the mouth of the skimmer.
  6. If there is a leak, you will see the food coloring move toward the pool wall.
  7. Mark the spot with duct tape so that you can patch the vinyl or repair the plaster.
  8. If neither of the above methods works, but you still have a strong suspicion, consider calling a professional pool company to check for leaks.

What Causes Swimming Pool Leaks?

Pools can last for decades if you care for and maintain them properly. That said, issues can occur, and some of these problems can cause leaking. The three leading causes of pool leaks are structural flaws, fitting faults, and plumbing problems.

Structural Leaks

A structural leak is a leak in the pool wall itself. For your average concrete pool, this means a crack in the shell. Structural leaks come from various factors, including ground movement, subpar engineering, pressure from groundwater, shifting soil, and alternative cycles of freezing and thawing that wear on the concrete.

Fitting Leaks

A fitting is anything that penetrates the pool’s shell, such as jets, skimmers, and lights. Since concrete pools are not watertight, fittings increase the chances of a leak.

When a fitting gets inserted into the pool’s walls, the builders typically plaster around it. These plastered areas are vulnerable to leaks.

Plumbing Leaks

The plumbing in a pool can be pretty fragile and must be correctly installed. These fixtures must be secure since any movement could lead to a leak in the piping or the pool shell.

Plumbing leaks are mainly from the plumbing system’s movement, which may be caused by settling of the ground near a pipe or corrosion.

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How to Fix a Leak In Your Pool

What do you do once you discover a leak?

Fixing Leaking Pool Pipes

Leaking pipes will often have water pooling underneath them. For these, you can plug the crack or hole with 100% silicone sealant and Teflon tape.

Fixing Leaking Pool Skimmers

Leaking pool skimmers are typically from the skimmer separating from the shell’s concrete. To be sure, submerge the skimmer by an inch or more. Turn off the pump and use the food coloring method to check if the skimmer leaks.

You can seal it with underwater repair putty from a hardware store or pool supply store if it does leak.

Fixing Vinyl Pool Liner Leaks

There are a few different ways to repair a vinyl pool liner, depending on how damaged the liner is.

Small Tear in the Vinyl Liner: Use a Vinyl Patch Kit

This method applies to above-ground vinyl liner pools. If the tear isn’t too large, a temporary solution is to apply waterproof tape to the rip. You need to use peel-and-stick patches or a vinyl patch kit for a more permanent fix, which you can get from a local hardware or pool store. The patch kit should come with specific instructions on how to use it. Read my in-depth guide on how to find an above ground pool liner leak.  And if you do not feel comfortable, contact a pool professional to help out.

Large Tear or Many Small Tears: Replace Vinyl Liner

Using a patch kit is the best and easiest option for vinyl pools if the tear is small and there are not too many areas to patch up. For larger repairs, you may need to replace the entire vinyl liner. For a step-by-step walkthrough of this, read my full article on replacing a vinyl pool liner.

If you have a concrete pool leak, you’ll need to repair the pool plaster, read my guide on pool plaster repair.

When To Contact A Professional

While certain pool leak fixes, such as patch kits and basic plaster repair, are fairly simple, things can get very complicated if the leak is in the plumbing or the deep end of the pool. Some pool leaks may be especially difficult to detect, so you may struggle to locate the leak in the first place. In this case, I recommend contacting a pool professional to handle the fix.  Leaks in your pool can get worse the longer you leave them, so it is best not to snooze on the problem. Some major pool leaks may require you to replace the vinyl liner entirely or do major repairs on the pool plaster, which are complicated fixes that you shouldn’t really attempt on your own unless you have a lot of experience.

Bottom Line

Ultimately, the critical thing to know is that any pool leak can be fixed and should not cause panic. You can fix the issue yourself in most cases without spending too much. By detecting a leak and applying the appropriate measures mentioned here, you should be able to enjoy your pool again.

Have questions? Send me a note; I’ll be glad to help.

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