Finding a pond leak isn’t easy. Our team is often on their hands and knees, moving things around, bending over, and sticking their hands in places.
The first thing to do is turn off any auto-fill devices and motors. Fill it back up (sounds weird, right?) and let your pond go for 24 hours. It’s best to not do this on rainy days and nights. If you have any fish, adding an aerator will help them breathe better during hot days.
Keep going until the water stops draining. If the water stops dropping, check the water level for the source of the leak (low edges, liner tears, concrete cracks, failed skimmer seals, etc).
We always check for the obvious first- large rocks that may settle and weight down liner, wet mulch areas, wet gravel, even the skimmer to liner connection.
If the pond drains to dangerous levels for any fish you can move them to a separate holding tub. The water in the tub needs to be from the pond. New water can cause them to go into shock.
If the water never drops or drops a very small amount during the first 24 hours, the leak isn’t in the pond basin.
If it isn’t the basin, the water loss is coming from somewhere between where the water exits the pond (plumbing) to where it goes back into the pond. The plumbing can be the hardest part to check because it’s usually underground.
You can also use the milk method to find a pond leak (or dye). Let the milk run from the top of the feature. Watch where it goes, as it’s likely to leak out with the other water. Don’t be shy about pouring it in, the leak area could be small and hard to see.