In Arizona's summer heat, a pool can lose around a quarter inch of water a day to evaporation, sometimes more on hot, dry, windy days. If yours is dropping noticeably faster than that, or keeps losing water in cooler weather, there's a good chance it's leaking. A simple bucket test will tell you which it is.
It's worth finding out. A leak wastes water, raises your bill, can wash out soil under the deck, and puts strain on the pump if the level drops below the skimmer.
How much evaporation is normal in Mesa?
Evaporation depends on heat, humidity, wind and sun. Mesa's summer combines all four, so pools lose water faster here than in most of the country. A pool that needs topping off a few times a week in June and July is often normal.
Some things increase evaporation:
- Water features like waterfalls and sheer descents
- An attached spa that spills over into the pool
- Running a heater
- Wind across an open, unshaded pool
A solar cover can cut evaporation significantly when the pool isn't in use.
The bucket test
This test compares your pool's water loss to evaporation under the same conditions.
- Fill a bucket with pool water and set it on the first or second step, so it sits at the same temperature as the pool.
- Mark the water level inside the bucket.
- Mark the pool's water level on the outside of the bucket, or on the tile.
- Leave the pump on its normal schedule and don't add water. Keep swimmers out.
- After 24 hours, compare the two drops.
If the pool dropped more than the bucket, the extra loss is likely a leak. Repeat the test with the pump off; if the pool loses more with the pump running, the leak may be in the pressure side of the plumbing. If it loses more with the pump off, it may be on the suction side or in the shell.
Where pool leaks usually are
The equipment pad. Check around the pump, filter, heater and valves for drips, wet ground or white mineral deposits. Pump shaft seals and filter O-rings are common culprits, and they're often the easiest to fix.
The skimmer. The joint between the skimmer and the pool shell can crack or separate, especially as the ground shifts.
Lights. Pool light housings and the conduit behind them are a frequent leak point.
Return fittings and drains. The seals around fittings in the pool wall and floor can loosen over time.
Underground plumbing. Pipes running between the pool and the equipment can crack, especially in older pools. This is harder to find and usually needs pressure testing.
The shell. Cracks in the plaster or the structure itself can leak, though these are less common than plumbing and fitting leaks.
Signs that point to a leak
- Water loss well above what the bucket test shows
- Soggy ground or puddles near the pool or equipment
- Cracks in the deck or tile that keep growing
- Air bubbles in the pump basket or returns
- Algae that keeps returning even with good chemistry, since fresh water keeps diluting the chlorine
- A water bill that climbs without explanation
Don't forget the auto-fill
Many Arizona pools have an automatic fill valve that tops off the water as it drops. It's convenient, but it can hide a leak for months, because the level never looks low. If your water bill has crept up, turn the auto-fill off before the bucket test so the results are accurate. A valve that sticks open can also overflow the pool and waste water, so it's worth having it checked during regular service.
The dye test
If you suspect a specific spot, like a crack or fitting, turn the pump off and let the water go still. Squeeze a few drops of pool leak dye or food coloring right next to it. If the dye gets pulled into the spot, water is escaping there.
What a pro will do
Leak detection usually starts with an inspection of the equipment and visible fittings, then pressure testing the plumbing lines one at a time and checking fittings and the shell with dye. Equipment and fitting leaks are often fixed in the same visit. Underground plumbing leaks may need digging or a separate repair. Many leaks at fittings, lights or the skimmer can be sealed with the water in place, or only slightly lowered, so the pool rarely has to be drained.
In Arizona, most repair work beyond small jobs should be done by a contractor licensed by the Registrar of Contractors.
Get it checked
If your bucket test shows more loss than evaporation, a local pro in Mesa, Gilbert, Apache Junction or Gold Canyon can track down the leak and quote the repair. Send a request below or call (480) 788-5344.