In this article
A falling water level is one of the most worrying things a pool owner notices, because you see it on the tiles every morning. Sometimes it is completely normal; sometimes it is the first sign of a leak that needs attention. This guide gives you an orderly way to rule out the simple causes one by one, so you reach a clear answer before paying for breaking or repairs you may not need.
Is a dropping level always normal?
Every open-air pool loses some water naturally, and the loss rises on hot, dry and windy days. Riyadh is dry for most of the year, so evaporation is more visible than in coastal cities. Normal loss has a pattern. It changes with the weather, eases on cool, calm days, and leaves no damp around the pool.
Abnormal loss is steady regardless of weather, increases suddenly from one week to the next, or always stops at the same line on the tiles. That points to water escaping somewhere.
Common causes of a falling level
- Evaporation from sun, dry air and wind, increased by waterfalls, fountains or running the filter at midday.
- Splash-out during heavy weekend use.
- Filter backwashing, since every backwash discharges water, more so when it runs too long.
- A faulty auto-fill valve or overflow line sending water to the drain unnoticed.
- Leaks in the plant room at pump, filter or valve joints, usually visible as water or damp on the floor.
- Buried pipe leaks between the pool and plant room, the hardest to spot.
- Shell leaks through concrete cracks, weak waterproofing or around fittings and lights.
An orderly home diagnosis
- Log the level daily with a small strip of tape on the tile at the same hour, noting weather and use.
- Pause additions such as auto-fill and backwashing during the test.
- Compare with evaporation using the bucket test explained in our bucket test guide.
- Test the pump by running it one day and leaving it off another in similar weather.
- Inspect the plant room for drips, damp or white salt deposits around joints.
- Note where the water stops if you let it drop for a while.
Reading the pump test
| What you see | Likely meaning |
|---|---|
| Bigger drop with the pump on | Leak on the pressure side, in return lines or joints after the filter |
| Bigger drop with the pump off | Leak on the suction side, which pulls air in while running |
| Similar drop either way | Shell, tiles or fittings |
| Water stops at the skimmer | Skimmer body or its connection |
| Water stops at the light | Around the light niche or its cable entry |
How Riyadh's climate fits in
High heat does more than raise evaporation. The daily swing between midday heat and cooler nights stresses grout, movement joints and exposed plastic fittings. Many leaks start or show up in summer, and owners blame evaporation, so treatment is delayed. If this summer's loss is clearly higher than last summer's in similar conditions, it deserves an inspection.
The lasting fix once the cause is known
- Fill valve or overflow repaired or replaced, often the simplest fix.
- Plant room joints remade with suitable materials and worn seals or valves replaced.
- Buried pipes pressure tested line by line, then only the damaged section is exposed and replaced.
- The shell treated by repairing the crack and rewaterproofing locally, or fully if the membrane is weak in several places.
- Fittings and lights resealed with their surroundings waterproofed.
At YAM Pools we start with an on-site inspection including pressure tests, then provide a written quotation for the identified source only, with a written warranty on workmanship and waterproofing. We serve Riyadh and every city in Saudi Arabia.
Before you call a technician
- Several days of level readings with weather notes.
- Your bucket test result.
- The difference between pump-on and pump-off days.
- The level where the water stops, if noticed.
- Any damp in the plant room or around the pool.
This information shortens the inspection, makes the diagnosis more accurate and helps you understand the report you receive afterwards.
Frequently asked questions
How much daily loss is normal?
There is no single figure for every pool, because evaporation depends on heat, wind, shade and surface area. The most reliable way is comparing your pool with a bucket of water beside it.
Could the auto-fill valve be the cause?
Yes. A faulty valve or an open overflow line can send water away unnoticed. Switch auto-fill off during the test and watch the overflow.
Why does the water stop at a certain level?
Because the leak is usually at a point on that level, such as the skimmer, a light or a wall crack. Once water falls below it, the loss almost stops.
Can I fix the leak myself?
You can check simple causes such as valves and visible joints, but buried pipe or shell leaks need test equipment and a specialist team.
