There are two types of leaks that are common with inground pools

That water leaking from your pool is going somewhere (generically). It’s leeching into the ground under and around your pool (specifically). When an inground pool leaks, the ground (under and around your pool) is severely compromised and weakened. Some examples are:

  • heightened amounts of ground water accumulation.
  • excessive soil saturation.
  • onset and rapid soil decomposition.
  • erosion of the soil under and around your pool.
  • undermining of the soil under and around your pool.

These are all problems. And these problems get worse and worse the longer the pool is allowed to leak.

As the ground is compromised, the pool will be sitting on disturbed and weakened earth. This will cause major problems to the pool structure. This  will also cause major problems to the underground plumbing and/or the pool deck. And, the cost for their repairs will be expensive. It will be much more than the cost would have been for initial leak detection and repairs. If you continue to allow your pool to leak, not only will you inevitably pay to locate and eliminate the leak source(s), but you will also be faced with the real potential for far greater structural problems and expenses.

There are two types of pool leaks:

  1. static leaks
  2. plumbing leaks

A static leak is a leak at the pool structure or perhaps around a fixture encapsulated inside the pool. Other static leak sources can be available too, depending on the pool. A static leak source can be anywhere inside the pool. The pool will continue to lose water until the water level in the pool reaches the static leak source. This is assuming there is only one static leak source. A pool may have one static leak source or multiple static leak sources.

A plumbing leak is a leak in the plumbing. This is mainly due to a break/crack in a pipe or a bad connection fitting. A pool may have on plumbing leak or multiple plumbing leaks.

Unfortunately, a pool may have a static leak and a plumbing leak simultaneously.

If a pool leak is suspected, it needs to be confirmed. As the onsite pool owner/operator, you really should take the lead in leak analysis. You have 24/7 access to the pool. And since you’re taking the lead, there is no invoice for these self-services rendered.

Evaporation

All pool owners must understand evaporation. Pools will evaporate. This is not a leak. This is evaporation.

During different times of the year, due to the temperature differential between the outdoor air temperature and the water temperature of the pool, due to wind, due to the location of the pool in the yard, due to a lack of wind barriers, due to sun/shade ratios, due to the surface area of the pool, and due to other sets of circumstances or variables, pool water will evaporate.

Due solely to evaporation, a pool can lose between 1/8″ to as much as 1/4″ of water max per day. Most pools – probably the clear and absolute majority of pools – will evaporate close to an inch of water per week. But a pool could evaporate about an inch-and-a-half of water per week when conditions are favorable.

If the pool is used a lot during the week, and by a lot of people each time that the pool is used, then the water loss can be even slightly higher due to splash-out.

And, if your pool is equipped with either a sand filter or a DE filter, then you will lose some water during the backwash process to clean your filter.

But, in a given week, most of the water loss – hopefully – is due to evaporation.

Leak Analysis

If your pool is losing 2″ of water per week, then you highly likely have a leak. It may even be a little less, and certainly anything more than 2″ is highly a leak.

If you cannot determine if water loss is due to leak or primarily due to evaporation, then try the clear plastic pitcher test.

→ The clear plastic pitcher test:

First, make sure the pool is filled to the standard operating level, which is half-way into the skimmer opening. Then, get a clear plastic pitcher.

You will need to place some weight in the pitcher. You can use some river rocks or a brick or anything weighted.

Place the pitcher on the top pool step (assuming that water is covering the top pool step, otherwise the next step down). Fill the pitcher with water so its level is the same as the water level of the pool. Note the time of day. Check the water level in the pool and in the pitcher in 24 hours:

  • If both are the same, then the water loss is due to evaporation. The pool does not leak.
  • If the water level in the pool drops more than the water level in the pitcher, then there is a leak somewhere with or within the pool. Evaporation occurs at the same rate, regardless of the surface area of the vessel. So, water in a pool (regardless of its dimensions and gallons) and water in a pitcher will evaporate at the same rate. For example, if one loses about 1/4″ of water in 24 hours due to evaporation, so will the other.
Notes for the clear plastic pitcher test:
  • Make sure that the clear plastic pitcher is not broken. If it is cracked or has a hole in it, then it will leak. This will void the results of the test. This test only works if the pitcher will hold water.
  • It is best to do this test when there in no rain predicted for at least the next 24 hours.
  • Stay out of the pool during this entire 24 hour test.
  • Allow your pool equipment to operate as normal during this 24 hour test.
  • Leave the pool uncovered during this 24 hour test.
  • Do not fill the pool during the test. So, if your pool has an automatic fill line, make sure it is off during the test.
  • If your pool does not have a step, then place the pitcher on the top tread of an in-pool ladder.
  • If there is nowhere to set the pitcher in the pool, then put the pitcher on the deck, next to the pool, and fill it about halfway full of water. With a black marker, put a mark somewhere on the pool sidewall (likely a skimmer faceplate) at the water surface to note the current level of the water inside the pool. Also put a mark on the clear pitcher to note the current water level inside the pitcher. Note the time of day. Check the water level in the pool and in the pitcher in 24 hours. Use a tape measure to measure from the black mark to the current water level in both – in the pool and in the pitcher.
Duration of the clear plastic pitcher test:

If the leak is insignificant, you might want to run this test for 2-3 days. This will give you a better overall view of the water differential, if any. If there is some differential after 2-3 days, but they are both still pretty close to the same level, then run this test another day or so. Even with an insignificant leak, you will have telling results within a week.

This clear plastic pitcher test will not pinpoint a leak source. It is just a test to prove if a pool leak exists or not.

Start with this simple and free test if any type of pool leak is suspected. If the pool does leak, you can then follow-up with a 24/24/24 test.

→ The 24/24/24 test

The 24/24/24 test is a three day test. You will perform three separate tests, all three for 24 hours each, one with the pump on and two with the pump off. This test is to help pinpoint the location(s) of the leak.

The first 24 hours:

For the first 24 hour test, you will operate the system per normal operations, with the pump on. All of the valves will be open. During this test, you will be operating the pool as it typically operates. Before the test starts, with a black marker, put a mark somewhere on the pool sidewall (likely a skimmer faceplate) at the water surface to note the current level of the water inside the pool. Note the time of day. Check the water level in the pool in 24 hours (it does not have to be exact, but make it close; i.e. if you start the test on Tuesday at 4:30 pm, then check the results on Wednesday as close to 4:30 pm as possible). Use a tape measure to measure from the black mark to the current water level in the pool. Note the amount of water loss.

Fill the pool level back to the original black line (from where the fist 24 hour test was started).

The next 24 hours:

For the next 24 hour test, you will turn the pump off and put a plug in each of the skimmers and each of the returns; the main drain(s) will have to be left as-is unless you want to hire a diver to plug the main drain(s). With this test, the plumbing – again, with the exception of the main drain(s) – will be removed from the pool. Once the skimmer(s) and return(s) are all plugged and the pump is turned off, note the time of day. Check the water level in the pool in 24 hours (it does not have to be exact, but make it close; i.e. if you start this test on Wednesday at 5:30 pm, then check the results on Thursday as close to 5:30 pm as possible). Use a tape measure to measure from the black mark to the current water level in the pool. Note the amount of water loss.

Fill the pool level back to the original black line (from where the fist 24 hour test was started).

The last 24 hours:

For the last 24 hour test, leave the pump off and unplug the skimmer(s) and return(s). Once the skimmer(s) and return(s) are unplugged, note the time of day. Check the water level in the pool in 24 hours (it does not have to be exact, but make it close; i.e. if you start this test on Thursday at 6:30 pm, then check the results on Friday as close to 6:30 pm as possible). Use a tape measure to measure from the black mark to the current water level in the pool. Note the amount of water loss.

Comparing the three 24-hour tests:

Compare your notes from the 3-day test. From the data collected with the three separate 24-hour tests…

  • did the amount of water loss change or stay the same with the pump on during the first 24 hour test and the pump off (with the skimmers and returns plugged) during the second 24 hour test?
  • Or, did the pool lose more water with the pump on during the first 24 hour test than it did with the pump off (with the skimmers and returns plugged) during the second 24 hour test?
  • did the amount of water loss change or stay the same with the pump off (and the skimmers and returns plugged) during the second 24 hour test and with the pump off (and the skimmers and returns unplugged) during the last 24 hour test?
  • Or, did the pool lose more water with the pump off during the last 24 hour test (with the skimmers and returns unplugged) than it did with the pump off (with the skimmers and returns plugged) during the second 24 hour test?

Just by calculating and reporting this information, this will save us time and you money during the leak detection phase(s).

Notes for the 24/24/24 test:
  • You definitely need at least 72 hours with no rain predicted to accurately complete these tests; rain will certainly void the results.
  • You cannot skip a day of measuring; missing a day of measurements will void the results.
  • Stay out of the pool during this entire 72+ hour test.
  • Leave the pool uncovered during this 24 hour test.
  • Do not fill the pool during the test. So, if your pool has an automatic fill line, make sure it is off during the test.
Results from the 24/24/24 test:

If the water loss is more (and quicker) with the pump on versus the pump off, if you cannot visibly see a leak at the equipment pad, then the leak is in the underground plumbing. While a pressure test is the best method to determine plumbing leaks, there is some information you can report that might help.

Track this information:
  • Check for bubbles under the pump lid when the pump is on and the equipment is operating per normal.
  • ​If water is lost when the pump is on and the equipment is operating per normal, if the leak is in the return piping back to the pool, then the rate/amount of water loss will likely be much more than a leak from a suction pipe (for the main drain(s) or skimmer(s) or perhaps a dedicated suction line).
  • ​If no water is lost when the pump is off and the skimmers and returns are plugged, you still cannot 100% conclusively verify that the plumbing for the skimmers and returns are not a leak source. This is where the third and final 24 hour test is needed. If no water is lost when the pump is off and the skimmers and returns are now unplugged, then you can just about 100% confirm that the skimmers and returns are conclusively not a leak source. However, if water is lost with the pump off (and the skimmers and returns unplugged) yet no water was lost with the pump off (and the skimmers and returns plugged), then you know the skimmer piping and/or the return piping is a likely leak source. This can be verified with a pressure test.

Take accurate notes during the 3 days and call us if something isn’t adding up or if you have questions.

A special note about the main drain during the 24/24/24 test:

Unless you hired a diver during this test, the main drain remain unplugged when the pump was turned off. If the main drain is a leak source, the rate of loss may be more/quicker with the pump off versus on. The main drain is a suction port, which is plumbed to suction piping; suction pipes are under vacuum when the pump is on. So, when the pump is on and the suction piping is under vacuum, if there is a break/crack in any suction pipe, the pump may be able to pull the water past the break/crack when the pump is on. So, maybe no water is lost when the pump is on. If this is the case, you will likely see air bubbles under the pump lid; as the pump is pulling the water past the break/crack, it will also draw in air from that break/crack, which will show up as air bubbles under the pump lid. With the pump off, there will be no vacuum created, so the water can leak through the break/crack statically.


Professional Leak Detection and Repair

As you complete the initial leak analysis, to include accurate note-taking, share the results with us and then we can discuss the next phase(s) for actual leak detection. Our initial visit is at no cost to you. Being onsite, this gives us the opportunity to hear your explanation of the leak, collect all of the information, and also perform some basic leak analysis and inspections. During this free visit, we will discuss the options for further leak detection (if needed) as well as the costs involved to perform various tests (some manual, some mechanical) to determine the source and location of the leak.

Perhaps you can help determine if your pool has a static leak, a plumbing leak, or both. This will lessen the cost to you and help streamline the leak detection process.


Contact Expert Pool Work, Inc. at 402-341-8132 or info@expertpoolwork.com to discuss your pool leak or submit a short form to schedule free onsite leak consultation.


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