Swimming Pool Leak Detection: A Comprehensive Guide

Do you have this lingering suspicion that your swimming pool is leaking?

It can be hard to tell for sure. For one thing, there are many possible reasons why a swimming pool is losing water.

But you can’t rely on guesswork alone. Building and maintaining a swimming pool is a huge investment, and you’re bound to suffer huge losses if you’re losing water all the time.

In other words, you can’t afford to sit idly by and make room for speculation.

So, what’s a pool owner to do?

On this page:

  • Here’s an idea: Do some detective work.

    But first, a word of caution: leak detection can be tricky. And if you want to achieve favorable results, you need to use a systematic approach.

    And we’ll be happy to provide you with the steps to do just that.

    Are you ready, my dear Watson?

    Let’s go hunt for clues.

    above ground pool

    Why Swimming Pools Get Leaks

    In order to detect pool leaks, some basic knowledge of why swimming pools get leaks is necessary.

    Pools are constructed to become watertight, and those made with the best materials should be able to hold water without any issues for a long time, especially if you perform backwash treatments on a regular basis.

    With that said, pools have an expected lifespan. After all, pipes get damaged, seals deteriorate, grounds erode, and screws get loose.

    Here are the common reasons why swimming pools get leaks:

    • Normal wear and tear.
    • Loose fittings around tiles, return jets, skimmer gasket, railings, etc.
    • Damaged plumbing below the deck.
    • Issues with the pump and the motor.

    Whatever caused your pool to leak, the repair must be performed as soon as possible. Otherwise, you’re going to lose plenty of water over time and experience floods. Moreover, pool leaks can cause the pool’s surrounding grounds to become saturated.

    Is My Pool Leaking? How to Tell

    The first order of business, of course, is to find out if your pool is leaking or not. Like every good detective, you can’t jump to conclusions.

    As stated earlier, there are many possible reasons why your pool is losing a lot of water, with evaporation being the most likely culprit. Strong winds, high exposure to sunlight, high temperatures — all these can contribute to evaporation.

    Which begs the question: Is my pool losing water due to evaporation?

    There’s one way to find out.

    Enter the so-called Bucket Method.

    The Bucket Method

    In this method, you’ll need the following:

    • 5-gallon plastic bucket
    • Duct tape

    And here are the steps to find out if your swimming pool is losing water from evaporation or from a leak:

    1. Put the 5-gallon plastic bucket on the second step of your pool.
    2. Fill the bucket with water until it matches the level of the water in the pool area.
    3. Mark the water level with duct tape.
    4. Turn off the pool’s pump or any device that fills the pool with water.
    5. Wait for at least 24 hours.
    6. Compare the water levels for both the pool water and the water inside the bucket to see if there had been a rapid decline. If they’re even, your pool may have lost water because of evaporation. If not, chances are your pool is leaking.
    7. Turn the pump on and repeat steps 1-6.
    8. If the pool water level is higher but the water is swirling due to pressure, the cause of the problem is probably your pool’s plumbing.

    How to Find a Pool Leak

    You already know your pool is losing water because of a pool leak. But where is the leak coming from?

    A pool leak could come from many possible sources. If you want to find where the leak is coming from, you need to be aware of the telltale signs.

    First, turn off the filtration system and observe at which pool opening the water stops draining. (Fair warning: Don’t do this test if you have a liner pool since it will cause the water level to drop rapidly.)

    Now, for some observations:

    • Did the water stop draining at the pool light? If yes, the source of the leak is probably the light housing.
    • If the water is dropping below the light, the leak’s source is probably the drain plug at the pool’s bottom.
    • Is the water stopping at the skimmer opening? If yes, the leak is likely coming from the skimmer or filtration system.
    • If the pump is running and you see air bubbles in the return line, the leak is probably in the filtration system’s suction system.
    • If the pool is draining fast while the pump is running, the leak is coming from the pool’s return lines.

    Find the Leak By Turning the Pumps and Filters Off

    Finding out if the pool is still leaking while the equipment is running is always a good place to start. If your pool is leaking water while your pumps and filters are off, that’s a sign that there’s a leak on the pressure side of the pool. These leaks, if left unchecked, can get bigger and stronger, making your pool lose water fast.

    If your pool is losing water even when your equipment is off, chances are you have a suction-side leak. In such cases, the water goes through a series of PVC pipes, causing the pipes to develop leaks after prolonged use.

    The reason why suction side leaks occur can be understood by learning first what exactly happens when the pump is running. Since a running pump creates a vacuum in the suction pipes, water is pulled out of your pool. This stream is powerful, so much so that it allows water to flow at shaft speeds through cracked pipes without leaking.

    But when the pump is off, that vacuum is gone. As a result, the water passes through the pipes slowly enough that it can leak through cracks and holes.

    Do the Dye Test

    If the procedures above are not producing any results, it’s time to put out all the stops and perform the dye (or food coloring) test. Do you have a bottle of dye or food coloring lying around your home? Now is the time to put it to good use. If not, you can buy a bottle of dye at the nearest hobby store or food coloring at any grocery store (buy the Pentair leak detection solution if it’s available).

    Squirt the dye in the water close to the spot where you suspect the leak is coming from. If the source of the leak is close by, the dye should move towards it. If the dye is staying put, move to another spot and do the test again.

    Pool Leak Detection Equipment

    When you’re losing copious amounts of water due to a pool leak, finding its source as quickly as possible is critical. Sure, the steps mentioned in the previous sections work to a certain extent, but they require a lot of work and time to be pulled off.

    If you want to detect leaks fast, you’d do well to use pool leak detection equipment. Sure, it will cost you, but it’s an investment that will pay dividends in the long run, especially if you own a big pool.

    So, without further ado, here are some pool leak detection equipment you can use to find pool leaks fast and with minimal effort.

    Pipe Probe

    The pipe probe is the most versatile equipment for leak detection. Powered by an LT1000 amplifier, the probe can detect vibrations over great distances. Want to detect leaks along the sides while standing up? The attachable soil probe helps you do just that.

    Acoustic Listening Device

    If you’re having a hard time finding the source of a leak, an acoustic listening device is an equipment that can help you pinpoint its coordinates. These highly portable devices are equipped with a listening stick and a ground microphone, allowing you to detect leaks even under concrete and behind walls. It comes with a sophisticated sensor that gives away signals if you’re moving away or moving closer to a leak.

    Pool Scope (Hydrophones)

    The pool scope is a long cable attached to a hypersensitive microphone, which you can use to detect leaks in narrow spaces, including pipes, return lines, main drains, skimmer lines, and more. Most pool scopes can snake its way into narrow spaces at a depth reaching up to 10 inches.  It’s super sensitive, and it increases in volume as you get closer to the leak source.

    Deck Plate

    A deck plate is a leak detection equipment that allows you to search for leaks with the least amount of effort. Thanks to its noise filtering technology and its accompanying pressure rig, the deck plate can spot a leak through hard, thick surfaces, whether it’s concrete, compacted soil, brick, or rock.

    What to Do if Your Pool Filter is Leaking From Top to Bottom

    above ground pool

    Having a filter system is essential because it regulates the collection of debris such as sand, gravel, dirt, and cinders that accumulate in the pool. In other words, the filtering system is what keeps the water in your pool clean, and more importantly, safe, at all times. There are many types of pool filters, but their main function is to catch all the dirt and debris, and to facilitate their proper disposal.

    If you notice that the water in your pool has been funky lately, chances are your pool filter is not functioning properly.

    In that case, the pool filter needs to be repaired before the problem gets worse. How you go about it depends on the nature and severity of the leak. Let’s examine the different scenarios of a leaking pool filter and delve into what must be done to fix them.

    Your pool filter is cracked

    It can be easy to determine if there’s a leak in your pool filters. If the water hasn’t been clean lately, the more likely culprit is a leaking filter. You’ll also notice that the pressure in your filter is irregular and that the leak is coming from the pool multiport valves.

    In this case, the best course of action is to buy a new filter (preferably one with a durable air relief valve such as those manufactured by Hayward). This is even more the case if you’ve been using your filter for over five years. We wouldn’t recommend it, but if you want to keep using it, buying a new tank half would make it workable. The problem with this option is that you’d end up replacing the filter anyway soon. This is hardly a surprise since a pipe that cracked once is more likely to crack again.

    To install the new filter, disconnect the leaking tank from the pipes and the pumps first. This procedure can be sensitive so don’t hesitate to hire a pool contractor if you’re not comfortable doing the replacement yourself.

    Leaks in the equalizer line

    The equalizer line is another common source of pool leaks. It’s also responsible for keeping the skimmer operational even if the pool water level drops below the skimmer’s opening. Such drops in water level, however, put your pool pump at risk for damages, especially since it’s connected to the main drain (this is why durable pool pumps, such as ones manufactured by Pentair Challenger and Intex, are most highly recommended).

    The equalizer line is often ignored because replacing it is expensive, not to mention that it takes a lot of time. With that said, not doing anything about it soon is a big mistake since a damaged equalizer line accounts for many cases of unexplained water loss.

    An equalizer line cannot be fixed once it’s damaged. The only option is to have it replaced. To unplug the faulty equalizer cord, the pool water level must be lowered so that the line can be drained of water and dried out. Before you do, make sure that both ends are plugged up or you run the risk of bacteria contaminating the pool.

    Leaks in the main drain

    A pool needs a reliable circulation system in order to be functional, and the main drain plays a huge role in that whole operation. Located at the pool’s deepest point, the main drain is not technically a drain. Rather, it’s used as an outlet that facilitates the passage of water through the skimmer, the filters, and then back to the pool through numerous inlets. Big pools typically have two or more main drains.

    Here are the steps to fixing a leaking main drain:

    1. Before proceeding, you need to empty the pool (make sure to turn off the power and the circuit breakers first). Check that the bottom of the pool is dry enough for repairs.
    2. Break up the concrete covering the leaking main drain with a jackhammer.
    3. Clear away any loose debris around the pipe.
    4. Find the leak.
    5. Cut out the section above ground and below it.
    6. Replace the section you removed with a new one and then glue them all back together.
    7. Mix the concrete and pour the whole lot into the hole until the pipe is all covered up.
    8. Let the concrete dry overnight.
    9. Create the plaster compound and apply it over the concrete until it’s level with the pool surface. Smooth it out with a trowel.
    10. Install the main drain cover.
    11. Refill the pool.

    Leaks in the Pool Shell

    The pool shell is what houses the pool water. As such, you can imagine what’s going to happen if that shell cracks or bursts. When the pool shell has a leak, there’s a high probability you’ll find bits of debris getting sucked into the crack.  A pool shell can be made of fiberglass, concrete, or vinyl.

    Before repairing the pool shell, you need to check the severity of the damage. Is it a mere hairline crack? Is the crack wide or deep or both?

    Fixing a pool shell with small cracks

    For smaller cracks, all you need to do is jump in the pool with a screwdriver in hand. Pry away any loose material from the crack before applying pool putty on it. Make sure to smooth it out with your hand.

    Fixing a pool shell with medium-sized cracks

    You need a different procedure if the crack is wider and deeper. In fact, you’ll need to drain the pool first. More importantly, you need to wear eye and ear protection as well as gloves, boots, and long pants. As you can already tell, it’s going to be a dusty and messy operation.

    Once the pool has been drained, chip away at the cracks with a 4-inch grinder until they become wider. If the crack is too small, a masonry drill will do the job. As you widen the crack, make sure to cut at an angle in a way that makes it easier to align the patching material.

    Once the cuts have been made, clear away any loose material with a garden hose.

    At this juncture, you can go ahead and fill in the crack using a pool plaster mix. For a stronger bond, make sure that the crack is wet before and after applying the plaster. You can lay a wet towel on the area to keep it moist.

    Fixing a pool shell with bigger and deeper cracks

    If your pool’s cracks are severe, do the exact steps mentioned above, but this time, make a horizontal cut every foot or so that is perpendicular to the crack. You must bore holes on both sides as well before reinforcing the bond with steel.

    This method works for bigger cracks because it keeps the pool wall intact on both sides. After the holes have been plastered up and all staples are in place, you can proceed in repainting and re-plastering the pool wall.

    How to Repair a Ruptured Pool Pipe

    Okay, so you’ve found out that the source of the leak is a ruptured pipe and you want to repair it yourself. Great job! Here are the steps to repairing a ruptured pool pipe.

    1. Mark both ends of the ruptured section with a line and then remove that section with a hacksaw or a PVC saw.
    2. Smooth the edges of the cuts with sandpaper.
    3. Measure the length of the gap left by the removed section.
    4. Cut a new piece of pool pipe (one with the same diameter) but with a length that is a half inch shorter than the length of the gap (this gives you some wiggle room for positioning the new tubing in place).
    5. Slide a coupling to each end of the new PVC pipe.
    6. Apply PVC solvent around the PVC tubing as well as the insides of the couplings where it will be installed. Allow the solvent to dry for at least one minute.
    7. Apply PVC solvent to the exterior of the tubing and the interior of the coupling before connecting them one at a time.
    8. Hold the connections together for at least 30 seconds.
    9. Do the same thing for the rest of the joints until they’re all welded securely together.

    Getting Quotes From Pool Leak Detection Companies Near Me

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    Let me guess: Your pool is leaking and you can’t be bothered to fix it yourself. By this point, the only choice you have is to hire professional help.

    That’s not in the least surprising. For one thing, pool leak repairs are complex, time-consuming, and require a lot of hard work. Your DIY skills can only help you up to a certain point. In the final analysis, hiring a professional contractor is almost always the best choice.

    But now you’ve reached a quandary: you don’t know exactly where to find a pool leak detection company that can do the job properly or charge you a fair price.

    There’s just too many things that can go wrong. And considering how big of an investment swimming pools are, it’s no exaggeration to say that you have a lot to lose.

    So, here’s a bit of practical advice: Get as many quotes as you can from competing contractors!

    You can’t afford to pick the first contractor that you come across, even if the offer looks good.

    Having many choices is a good thing. It gives you a good idea of what works and what doesn’t, as well as what’s considered a fair price and what’s not. It lets you know what you’ve been missing out on. It lets you consider alternatives if you have to settle.

    In simpler terms, having many quotes to choose from gives you more opportunities to find a contractor or contracting company who fits your needs.

    As for finding these contractors, there’s always the web. Also, don’t forget to ask for referrals from friends.

    But if that doesn’t work out for you, we’re offering you another solution.

    Thanks to our contractor database, you can get up to 4 quotes from competing contractors– completely free of charge!

    Note the emphasis on the word “competing.” This means that each contractor you’ll get in contact with knows he or she is but one choice among many. Which means everyone is going to make an effort to provide a quote you can’t resist.

    All you need to do is fill out our form. That’s all there is to it. No BS, no commitments involved.

    Want to have your leaking pool fixed once and for all? Take this first big step by taking advantage of our free service!

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