Why Your Pool Is Losing Water (And How to Fix It)
Normal Water Loss vs a Pool Leak
It is normal for swimming pools to lose a small amount of water due to evaporation, especially during hot and windy weather.
However, when the water level drops faster than normal, it may indicate a leak or structural problem.
Typical evaporation may cause water levels to drop a few millimetres per day, but larger or continuous drops may require investigation.
Common warning signs of a pool leak include:
• water level dropping quickly
• needing to refill the pool frequently
• cracks visible in the pool shell
• damp areas around the pool
• air entering the pump system
When these signs appear, it is often best to inspect the pool carefully to determine the cause.
Common Reasons Why Pools Lose Water
Swimming pools can lose water for several reasons, ranging from minor equipment leaks to structural damage.
Understanding the possible causes helps homeowners identify when professional repairs may be needed.
Structural Pool Cracks
Cracks in the pool shell are one of the most common causes of ongoing water loss.
Structural cracks may develop due to:
• ground movement
• poor original construction
• ageing concrete structures
• hydrostatic pressure
These cracks often allow water to escape slowly over time.
Proper structural repairs usually involve stabilizing the pool shell using reinforcement techniques such as steel crack stitching, followed by protective resurfacing.
Worn or Deteriorating Pool Surfaces
Older pool finishes such as marbelite can become porous or deteriorate with age.
When this happens, the surface may allow small amounts of water to seep through.
Resurfacing the pool with a modern finish such as fiberglass lining can restore the waterproof barrier and extend the life of the pool.
Leaking Pool Pipes
Swimming pools contain underground plumbing that circulates water between the pump, filter, and pool.
Leaks in these pipes can cause continuous water loss and may require professional leak detection.
Pool Equipment Leaks
Sometimes the leak is not in the pool itself but in the equipment.
Possible sources include:
• pump connections
• filter systems
• valves and pipe joints
• backwash lines
Checking equipment areas for wet spots or dripping water can sometimes reveal the issue.
How to Test If Your Pool Has a Leak (Simple Bucket Test)
One simple way to determine if your pool may have a leak is the bucket test.
Steps:
1 Fill a bucket with pool water.
2 Place the bucket on a pool step so the water inside matches the pool level.
3 Mark both water levels.
4 Leave for 24 hours without using the pool.
If the pool water level drops more than the water inside the bucket, the pool may have a leak.
When to Call a Pool Specialist
Some pool leaks are small and easy to identify, but others require professional inspection.
You should consider contacting a pool specialist if:
• the pool loses water every day
• cracks are visible in the pool shell
• resurfacing keeps failing
• damp areas appear around the pool
• water loss increases over time
Early repairs can prevent larger structural damage and expensive renovations later.
Structural Pool Repair and Leak Solutions
When leaks are caused by structural cracks, the repair process usually involves more than simply patching the surface.
Professional structural repairs may include:
• identifying the structural cause of the crack
• stabilizing the structure with steel crack stitching
• reinforcing the repair area
• applying a durable protective finish such as fiberglass lining
These methods help ensure the repair lasts long term.
Saving Your Pool Water During Repairs
Major pool repairs sometimes require draining the pool before work can begin.
Instead of wasting thousands of litres of treated water, Crispy Pools can store the water safely using temporary water storage bladders during the repair process.
This allows homeowners to:
• avoid expensive municipal refill costs
• conserve water
• refill the pool quickly after repairs
Because Crispy Pools owns its own water storage systems, clients avoid expensive rental fees often charged by other contractors.
Experienced Supervision on Every Project
All major repairs and renovations are personally supervised by Chris, who brings more than 15 years of construction and pool renovation experience.
Chris focuses on identifying the root cause of pool problems, ensuring repairs address structural issues rather than simply covering them.
Direct supervision helps ensure repairs are completed correctly and built to last.
FAQ – Pool Losing Water
Why is my pool losing water every day?
Small amounts of water loss can occur due to evaporation. However, if the pool loses water every day or requires frequent refilling, it may indicate a leak in the pool shell, plumbing, or equipment.
How much water loss is normal in a swimming pool?
Most pools lose a small amount of water through evaporation, especially in hot or windy weather. A loss of a few millimetres per day is normal, but larger drops may suggest a leak.
Can a crack in a pool cause a leak?
Yes. Structural cracks in the pool shell are a common cause of leaks. Water can escape slowly through these cracks and worsen over time if not repaired properly.
How do professionals find pool leaks?
Pool specialists inspect the pool structure, plumbing system, and equipment to identify the source of water loss. In some cases pressure testing or specialized leak detection methods are used.
Can a leaking pool be repaired without replacing the entire pool?
Yes. Many leaks can be repaired using structural crack repair techniques, resurfacing, or plumbing repairs depending on the cause of the leak.
Is fiberglass lining good for leaking pools?
Fiberglass lining can be an excellent solution after structural repairs because it creates a seamless waterproof barrier that helps protect the pool shell.