A Comprehensive Guide for Pool Leak Detection to Homeowners

The luxury of a pool comes with costly installation, operation, and maintenance.  Some pool owners cut operational and maintenance costs by doing the maintenance, testing, and repair by themselves. One of the problems most pool owners encounter is a pool leak. Sure enough, it is easy to just call a professional to conduct a swimming …

The luxury of a pool comes with costly installation, operation, and maintenance. 

Some pool owners cut operational and maintenance costs by doing the maintenance, testing, and repair by themselves.

One of the problems most pool owners encounter is a pool leak. Sure enough, it is easy to just call a professional to conduct a swimming pool leak detection and resolve the problem, but it comes with a cost. 

So in this article, we will help you save money by covering all you need to know about pool leak. After reading this article, you will be fully equipped with the knowledge required to perform basic pool leak testing and repairs, and when to call a professional to seek help.

Why Should You Be Concerned About a Pool Leak?

There are three main reasons why a pool owner should be concerned about a pool leak. 

Small Cracks In The Swimming Pool Can Lead To Leaks
Prevent losses from unaddressed pool leaks due to pool cracks

The first one is that it deteriorates the pool’s life and equipment faster. For example, an unaddressed pinhole leak in your pool could lead to larger pool holes and cracks. This would mean more water loss and an increased water bill. Another example, an unresolved leak in the filters, or the pump system can lead to air circulating in the pipes. The air in the pipes can cause cavitation that will damage your pool equipment.

The second reason is it increases your monthly water bill. A small pinhole leak in the system can lead to almost 4 cubic meters of water loss per day. So let’s say if the rate per cubic meter of water is $3.00, then your monthly water bill would increase by $360. Take note that this amount does not include the sewer rate charges in your state.

The third reason is that pool leak does not help in Earth’s sustainability. As much as possible, we need help in the effort of saving and conserving water.

Swimming Pool Leak Detection – What Are the Signs of Leak?

There are many signs that your pool may have a leak. You can use the list below during your pool leak detection.

  • Your swimming pool loses more normal water evaporation – The normal water loss due to evaporation is one-eighth (⅛) of an inch. So if you are losing more than that, you may have a pool leak. To measure water loss, you can use the bucket test that we will talk about later in this article.
  • Your pool circulation system has air – Due to water leak, air may enter your pool system. You can check for air by touching the pipes if it is warmer than usual (compressing air increases its temperature). If you have a purge valve in your system, you can try opening it and if air escapes first instead of water then you may have a pool leak. 
  • Wet or soggy spots around the pool area – Pool leaks will seep into the surrounding area, so if the land around the pool has wets or soggy spots then you may have a pool leak.
  • Shifting pool deck – If during leak detection you have noticed that your pool deck has lifted or sunk, you may have leaks in your pool.
  • Noticeable cracks in the pool – One of the best ways to test if you have leaks on pool cracks is the dye test. We will talk about the dye test later in this article.
  • An increased pool water refill – If you’ve noticed that you are adding more water than usual, then your pool probably has cracks.
  • A spike in your water bill – Your monthly water bill can also be an indicator that you may have a leak if you have no other leaks or plumbing problems inside the house.
Steam Forms Above The Pool Due To Water Evaporation
Measuring the water levels of your pool can be a test to know if you have leaks

Now that we’ve talked about all the possible signs of pool leaks, let’s move on to the possible causes of leaks.

Swimming Pool Leak Detection – Possible Causes of Leak

Vinyl Liner Holes or Pool Cracks

For pools that have vinyl liner as its waterproofing, one of the most common leak points is a pinhole on the liner. During the lifespan of your vinyl liner (most lasts from 10 to 20 years), you are bound to encounter pinholes or gashes. 

It is almost the same for a concrete pool, you need to look out for cracks and gaps on the concrete. 

The easiest way to check is to lower the water level of the pool then visually check for cracks, gashes, and gaps. After the visual inspection, you can use the dye test to verify.

Pool Filter, Water Pump, and Fittings

You can easily check if your pool filters have leaks. In the location of your pool filter, just observe if there are wet patches on the floor and you can easily trace where the leak came from. Leaks on pool filters can be due to the tank itself or the pipes and fittings. Replace the parts immediately.

Pool Skimmers

During leak detection, one of the most common problems is cracks in the pool skimmers. This problem is due to the skimmers’ expansion and shrinkage during the changes in season and the temperature. Verify the leak by doing the dye test. Don’t worry, skimmers are one of the pools’ components that’s easy to repair 


If you have an inground pool, and you’ve checked all the possible leak causes above, you may have a big problem with the underground plumbing. This is the time where you should consult a professional leak detection company. 

How Much Can I Save by Doing the Leak Detection and Repair?

You may be skeptical if doing the leak detection and repair on your swimming pool by yourself is worth the effort. So check the price breakdown below on the estimated leak detection and repair costs from professional leak detection companies.

  • Leak detection only – $300 to $500
  • Small vinyl repairs – $400 to $600
  • Plumbing repair – $400 to $700
  • Concrete pool repair – $700 to 1,000$

Take note that these are estimated costs from past transactions. Prices may vary due to factors such as location, pool size, and the scope of repair or replacement works. 

So is it worth it? Yes! Doing it by yourself will cost less way than those prices above. 

Swimming Pool Leak Detection Test That You Can Do

The dye test and bucket test are simple tests that you can do by yourself. All the materials are cheap and can be bought in almost any local store.

Dye Test

The materials that you’ll need for this test are a liquid dropper and a dye (pick an easily noticeable color like red or blue). You can easily buy these materials from a local grocery store or hardware. 

Take note that the dye test is used to verify a leak point that you suspect. So before conducting the dye testing, you first need to identify possible leak points by visual inspection. This test can be done on cracks, gashes, gaps, skimmers, screws, fittings, and other possible leak points.

As a safety measure, make sure that there are no other people in the pool. Afterward, proceed to the possible leak point. Fill the dropper with dye and squeeze out a small amount in the water near the possible leak point. 

If the dye does not seep into the possible leak point then there is no leak in that area. Do the same procedure on all of the suspected points of leaks.

Bucket Test

The bucket test is used to verify if a pool has a leak. This is done by comparing the water level of the pool to the bucket. Theoretically, a pool should not lose more water aside from evaporation. Also, this test does not pinpoint the location of the leak, it just confirms that a pool has a leak.

The materials needed for the test are, of course, a bucket (preferably clear or translucent), duct tape (preferably a colored one), and weights (preferably something that does not absorb water).

To set up the bucket test, place the bucket with weights at a step of the pool. Take note that the bucket should not be submerged in the water. Then fill the bucket with water to match the water level of the pool. Once the levels have matched, mark with the colored tape. Then leave it for 24 hours (the pool should not be used during the test).

After 24 hours, if the level of the pool water outside is less than the level of the water in the bucket then you have leaks in your swimming pool.

Repairs That You Can Do

Here are the repairs that you can do on pools without the need for professional help. Doing this by yourself is way cheaper than outsourcing the work.

Repairing A Large Crack On The Pool Floor
Save money by doing the repairs yourself

Pool Cracks

For a swimming pool made with concrete, repairing cracks and gaps is quite easy. You just need to seal it with concrete putty, silicon, or plaster mix that has waterproofing capabilities. For large gaps, it is advisable to use plastic mold injection for a tight seal. Then apply a plaster mix after. 

Vinyl Liner Holes

For pools that have vinyl liners, you need to prepare a vinyl patch kit for the pool repair. Vinyl patch kits are easy to use. 

First, measure the size of the hole or gash then cut out a patch that is double the size of the area that needs to be patched up. Put the vinyl adhesive on the patch and mix a little water on the adhesive. Then apply the patch with adhesive on the leaking area.

It is common to experience around two to three holes in a year. So if you’re experiencing many holes repairs than usual and your vinyl liner is quite old, you may need to consider replacing the whole vinyl liner.

Water Pump and Fittings

Leak on pumps and fitting can be easily spotted. Usually, you can find wet spots on the ground where the leak comes from.

A Pump Circulation System Complete With Pump, Filter, And Fittings
Trace leaks by looking for wet stains on floor of the pump room

When you find a wet spot on the ground, trace where it comes from and check if the fitting or the pump can be repaired. If not you’ll need to replace it to prevent more losses.

Pool Filter Replacement

Leaks on pool filters are rare. Check if the leaks come from the fittings or the filter tank. If repairs are not possible then proceed to replace the leaking part to prevent more losses.

Your filter may be leaking due to a lack of maintenance and cleaning. For example, if the laterals and buffers are clogged, the water can seep through the multiport valve or gauge. So make sure that you clean your filters regularly.

Pool Skimmer

During the leak detection, you may find your pool skimmers as the leak point. But don’t worry, the skimmers are easy to repair. 

Lower the pool level just enough to empty the skimmer. Then remove the strainer in the skimmer and proceed to check cracks or damages on the walls of the skimmer. Apply concrete putty mixed with waterproofing additives and let it dry. Place back the strainer and test again.

When to Call for Professional Help

When you are done with all the testing that you can do by yourself and there are still leaks, then it’s time to ask for professional help. The leak cases below need the skills of the professionals.

Vinyl Liner Replacement

When you’ve done patching up the damages on the liner but it’s still leaking, you may need to replace the vinyl liner completely. The liner in many areas may have become so thin that it lets the water seep through.

Total Replacement Of Pool Vinyl Liner
Seek professional help when replacing a pool’s vinyl liner

Replacing the vinyl liner is quite costly (around $2,000) but it will benefit you in the long run. The replacement will take around 2 to 3 weeks. 

Underground Plumbing

Hopefully, your leaks do not come from underground plumbing problems because this is the most costly problem and the most tedious. Depending on conditions, the project involves the excavation of your pool area, plumbing checks, pipe replacements, new pool installation, and landscaping.

An underground plumbing repair may take 1 to 2 months and may cost you around $3,000 to $5,000. 


You are now ready to do your own leak detection. So go ahead and try out the pool leak detection techniques that we’ve talked about. 

Was our leak detection guide on swimming pools helpful? Comment down below to let us know your thoughts.

Learning more about pool maintenance doesn’t end here. We still so many articles that will guide you as pool owners.

  • Do you have cloudy pool water? Click here to learn how to fix it by yourself.
  • One of the pool maintenance that you can do yourself is replacing the pool filter sand.
  • To fully enjoy your swimming pool experience, heating your pool is essential. Learn how to heat an above ground pool.

Head over to Pinterest for more pool design ideas that are suitable for your home.

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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