How to Diagnose a Pool Leak

The most obvious sign of a pool leak is water loss, but are you aware of some of the other tell-tale signs? Keeping an eye out for these warning signs can help you diagnose a pool leak early on and avoid potential costly repairs later on. 

Even the most experienced pool owner can be terrified at the first sign of a potential leak; like most problems, the best way to deal with a leak is head-on, armed with the correct equipment and knowledge. The first step is to understand when to look for leaks. The facts are, a leak in the pool structure could cause damage to the substrate around the pool as well as sinkholes.

Typically there are 5 main causes for a pool leak.

  1. Mechanical Issues
  2. Structural Damage
  3. Plumbing
  4. Broken Pipes
  5. Loose or Broken Fittings

Diagnose a Pool Leak

Some Water Loss Is Typical

Water loss in a pool does not always imply that it is leaking: evaporation and splashing are common causes. If such possibilities are ruled out, it's time to figure out where the leak is originating from. A pool leak is indicated by pool water pooling in the yard, damaged tiles or concrete, and fluctuating chemical levels.

The problem with pool leaks is that they can happen almost anywhere, both within and outside the pool. The most difficult part is usually locating the leak.

Tiles Are Cracking

When a pool leaks, the surplus water causes the surrounding ground to become unstable. As a result, the tiles that surround the pool may begin to fracture or move. If you notice gaps and cracks, it's possible that there's been a leak for some time and the water has crept further outward.

Puddle on The Lawn

Soppy wet ground is yet another clue that you may be dealing with a pool leak. The leak could be indicated by uneven lawn growth or muddy places around the pool area. 

Water Bill Going Up

Your water bill is another good indicator of leakage. Auto leveling pools may use enough extra water to affect the cost where it becomes noticeable on your monthly bill. If your water bill increases by an unusual amount, your swimming pool could have a leak that is costing you money every month.

Water Around The Equipment Pad

Not all pool leaks occur on the actual pool itself. If you notice water near your pool's equipment pad, investigate the area to ensure the water is not the result of a leak. Leaks can occur in a variety of places on the equipment pad, including the valves, filter, heater, and pump. Keeping a close eye on your pool equipment pad for a day or two generally reveals if that is the source of the leak.

Corrosion Is a Key Indicator

Severe corrosion on pipes and pumps surrounding the pool, as well as stagnant water (despite no recent rainfall), are usually signs that your pool is leaking.

Algae Grows

When new, untreated water is put to a leaking pool, algae development occurs. This untreated water causes chemical changes, which could foster the growth of algae. Rather of continuing to treat the water, you might want to look for a leak.


The Bucket Test

On the second step of your pool, place an empty 5-gallon bucket in the water. Fill the bucket with water to the same level as the pool. Mark this level inside the bucket with a marker or duct tape.

Pool Leak Detection

At the skimmer, mark the pool's water level. Mark the water level with a piece of tape or a grease pencil. After 24 hours, go back and check the mark. Each day, your pool should lose no more than 1/4 inch per day. If you notice your pool losing substantially more water than that, odds are good there could be a leak.

Finding The Pool Leak

The leak is most likely in the skimmer or filtration system if the water stops at the bottom of the skimmer opening (including the pipes). If you suspect a filter system leak, take the following steps:

First, examine whether there are any air bubbles in the return line when the pump is working. If this is the case, the filter system's suction side is probably leaking. 

The leak is most likely at the light housing if the water stops at the light. If the water level falls below the light, there could be a leak in the pool's drain.

The leak is on the return line side of the system if the pool is losing more water while the pump is working. In this instance, look for running water in the waste or backwash lines. Look for something that appears like a fracture, gap, or tear in the skimmer, light, or liner as well.

Dye Testing For Leaks

For this test, the pump should be turned off and the water should be completely still. The colored dye will be pulled into any crack or fissure where the leak is occuring. The dye marks the location as well as the flow of water into the crack. 

Dyes can be used on all types of pool surfaces, including vinyl, fiberglass, gunite, and cement. On a vinyl pool with a dark blue surface, fluorescent yellow dye will work best. This test works on inground and above ground pools. If you have trouble detecting the source of the leak crack, one of our expert leak detection professionals who knows what to look for in the water may be able to find it faster.

Finally, if you fear you have a leak the best recourse is always to call a professional that specializes in pool leak detection and can diagnose whether you have a leak or not and where the leak is located. The Pool Surgeon has helped hundreds of homeowners throughout Dallas and Fort Worth diagnose and fix pool leaks. Our expert service helps homeowners avoid costly pool repairs and water utility charges.

Leave a Comment