Why is my pool losing water?

Roughly a quarter inch a day in summer, sometimes more. Sun, heat, wind and low humidity all speed it up, and waterfalls, spillovers and a heated pool add to it. In winter it slows down. Splashing and backwashing the filter take water too, so a busy pool with a sand filter drops faster than a quiet one.

Do the bucket test. A bucket sitting on a pool step feels the same sun, heat and wind as the pool, so it loses the same amount to evaporation. If the pool drops more than the bucket over a day, the difference is a leak. The steps are below.

Run the pump on its normal schedule during the test, and do not test on a rainy day.

A pool that loses more with the pump running usually has a leak on the pressure side, the plumbing after the pump that pushes water back to the pool. Check the equipment pad first: the filter, the valves, the heater and the unions are where small leaks show up as damp spots or drips. A filter leaking from the top or a backwash line that keeps running is a common one.

A pool that loses more with the pump off usually has a leak on the suction side, the lines that pull water to the pump, or in the shell itself. Watch where the level stops. If it drops to the middle of the skimmer and stops, the skimmer is the suspect. If it stops at the light, look at the light niche.

Look for the easy ones first, then call a leak detection company.

• Wet spots in the yard, soggy ground near the equipment or between the pool and the pad.
• Cracks in the plaster, tile line or around the skimmer.
• A dye test. With the pump off and the water still, squirt a little pool dye near fittings, the light and cracks. If the dye gets pulled in, that is your leak.

For a leak you cannot find, a leak detection company pressure tests the lines and listens for it, usually without digging up the deck.

Yes, but less. A pool loses less to evaporation in cooler weather, though a heated pool on a cool dry night can still lose a fair amount. If a pool drops as fast in January as it did in July, test it.

Run a hose until the level is back to the middle of the skimmer opening. Too low and the skimmer sucks air, which is hard on the pump. If you fill from a well, add a metal sequestrant, because well water here often carries iron that stains the plaster. See how to remove well water stains. And never drain or let a Florida pool get very low on purpose without a plan; should I drain my pool explains why.