Why is my pool losing water?

Overview

A falling waterline is evidence of water loss, not proof of where the water is going. Weather, swimmer use, backwashing, an overflowing waste line, a plumbing fault and a shell leak can produce similar observations. Record the loss before choosing a repair.

Check first

• Mark the waterline and record the time, weather, pool use and whether the pump was running.
• Check the backwash or waste outlet for flow when the valve is in its normal filter position.
• Look for damp ground, wet equipment pads, drips at unions and water tracking from the filter or heater.
• Confirm whether recent vacuuming, backwashing, heavy swimming or overflow lowered the level.
• Compare loss with the system running and stopped only if normal operation is safe. Do not defeat timers or protection devices.

Stop and call a technician

• The level is dropping rapidly or approaching the skimmer opening.
• Water is entering an electrical area, building, retaining wall or neighbouring property.
• The pump will not remain full of water or is repeatedly losing prime.
• Cracking, ground movement or sudden structural change is visible.
• The waste line flows during normal filtration and the valve position is already correct.

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