If your pond continues to lose water after the pump is turned off, the water loss may be caused by a leak in the pond liner, a low pond edge, an improperly sealed skimmer faceplate, or natural evaporation.
When the pump is off, water is no longer circulating through the waterfall or stream. Continued water loss may indicate a problem within the pond itself.
How to locate the water loss
- Turn off the pump. Unplug the pump and allow the water to settle.
- Mark the water level. Use a piece of tape or another visible marker to identify the starting water level.
- Monitor for 24 hours. Check whether the water level continues to drop.
- Observe where the water stops. If the water continues dropping and then stabilizes, inspect the pond at that water level for a possible leak.
Important: Do not allow the pond water level to drop so low that fish or other aquatic life are at risk. Maintain adequate aeration during testing.
Common causes of water loss when the pump is off
- Damaged pond liner: A puncture, tear, or damaged seam may allow water to escape.
- Low pond edges: Settled soil or displaced liner may allow water to escape over the pond's perimeter.
- Skimmer faceplate leak: An improperly sealed skimmer faceplate may allow water to escape around the skimmer opening.
- Evaporation: Some water loss occurs naturally, even when the pump is not operating. Hot, dry, or windy conditions can increase evaporation.
What should I do if the water continues to drop?
If the water level continues to decrease:
- Check the exposed pond edges for low spots or wet soil.
- Inspect the pond liner near the level where the water stops dropping.
- Check around the skimmer faceplate for signs of moisture or leaking.
- If liner damage is found, use an appropriate EPDM pond liner repair product according to the manufacturer's instructions.
If the water level remains stable with the pump turned off but drops when the pump operates, investigate the waterfall, stream, plumbing connections, and other circulating components.
For additional guidance, see Aquascape's guide to finding and fixing pond leaks.
Note: If the leak cannot be located or repaired, consider having a qualified pond contractor inspect the pond.