How to Locate a Leak in a Pond Liner

A carton of heavy cream can help you locate that pond leak.

Pond liners are supposed to be durable and long-lasting. But because they're not indestructible, leaks are bound to happen. Patch kits are readily available to repair liner leaks; it's pinpointing the location of the leak that's tricky. Fortunately, there are several ways to find that hole.

Things You'll Need

• Milk or heavy cream

Instructions

1. Fill the pond to its usual full level.

2. Turn off fountains and filtration systems to calm the water.

3. Drizzle heavy cream into the water, a little at a time, about a foot away from the edge of the pond.

4. Follow the path of the cream. If there's no leak, the cream should settle straight down to the bottom of the pond. If there's a leak, the cream will be drawn toward the exit point of the water. If it's a slow leak, the flow will not be strong enough to draw the cream, in which case, go to the next step.

5. Let the water drop to the leakage level. It may take a few days to level off but you will be able to conduct your investigation along the waterline after the water drop stops.

6. Press the liner along the water line. Going an inch at a time, press the liner against the wall of the pond. The area where the water leaks out of the pond will be soft, because leaking water will erode the ground behind the liner wall.

7. Run your fingers against the liner to locate the puncture or tear.

Tips & Warnings

• Cream is used because it is not toxic to fish. Food dye works just as well.

• Pond liners are prone to leaks along folds and creases. Check first for tears underneath folds and along creases.

• Check the perimeter of the pond in case the leak is caused by a collapse in the liner's edge.

• If all efforts to locate the leak fail, you may need to empty the pond, remove the liner and inspect it for holes from underneath. Raise the liner against the light and look for holes and tears.

Resources

• "Encyclopedia of Aquarium and Pond Fish"; David Alderton; 2008