Repairing the leaks in plastic pond liners is a standard maintenance requirement for pond owners. Repairing the leaks prevents serious water loss and protects the pond from any bacteria that may be in the contaminated outside soil. For the safety of all living creatures in the pond, be sure to check for leaks at the beginning of spring each year.
Remove all the fish from the pond and place in a holding tank. Drain the pond to below where the hole is located. If you are unsure where the hole is located, use a medicine dropper and some milk to find the leak.
Scrub the entire area around the hole with naptha soap and an abrasive sponge to remove any dirt and grime.
Rub the area dry with paper towels. Verify that the entire surface is completely dry before applying the tape.
Measure the hole with a tape measure and add an additional inch around all the edges. Cut out the patch from its roll to match your measurements. Apply the sticky side of the patch to the area and rub firmly with a roller to establish the strongest bond.
Cover the sides of the patch with lap sealant and allow the patch to air dry for 24 hours before adding any additional water to the pond.