How do I mend a pond liner without having to replace it?


We built our coy pong nearly 20 years ago, then enlarged it and relined it about 10 years ago. We are pretty sure the liner has been torn or punctured because the water level drops about 7 inches every time the pond is filled. The pond is approximately 13' x 16' and, honestly, in all likelihood needs a new liner. We would appreciate any suggestions regarding how to find the leak and maybe avoid the labor and expense of a new liner. Thanks so much!

  5 answers
  • Kmdreamer Kmdreamer on Aug 07, 2018

    If the liner is plastic then you could repair like a pool liner with pool patch kit . Or there’s is a gorilla glue that is water proof just find something to put over the whole and glue it on

    • Mary Noll Mary Noll on Aug 07, 2018

      Thank you, Kathy! I appreciate the suggestions; first we'll have to find where the liner is actually leaking. I'm starting to think, because of its age, we'll need to replace the liner.

  • Thelma Thelma on Aug 07, 2018

    Fill the pond up to the level it leaks down to, wait to see if the level stays the same, if it does, add another inch of water, wait to see if the level stays the same, repeat the process until the water level goes down. Now you will know that the leak spot is within that 1" area somewhere around the pond. Use your hands to find the leak, then put a large piece of Flex Tape above and below the area - to be sure you get good coverage, around the entire pond at that level. Fill pond on up above the tape and see if it leaks. The pond liner may have holes in it at several different heights. Hope this helps.

    • Mary Noll Mary Noll on Aug 07, 2018

      Thank you, Thelma; this is a great suggestion, and it does make me consider that there may be more than one leak. We will try your idea and see if this solves the problem. Thanks again.

  • Kathryn Kathryn on Aug 07, 2018

    to find the leak, you will have to remove the liner and put some water on it to see the leak. to fix it, there are some super products on the market now, flex seal, flex tape, etc. they are supposed to work in water. they even have tape that can be applied in the water!

    • Mary Noll Mary Noll on Aug 07, 2018

      Thank you so much, Kathryn, but we would have a major problem removing the liner from such a large pond, and our filtration tubes run along the bottom of the pond on top of the liner. We would like to find a solution that avoids removing/replacing the liner. Thanks for your suggestion, though.

  • Janice Janice on Aug 07, 2018

    Hi Mary, I did some searching for you and found this info. It is about a swimming pool but the same methods may apply to your coi pond. Sounds like you've gotten good use out of your old one though. I hope this is helpful..........

    • Mary Noll Mary Noll on Aug 07, 2018

      Janice, thank you so much for such a quick and helpful response! I will take a careful look at the link you provided. Thanks again.

  • Thelma Thelma on Aug 07, 2018

    Flex Tape, the one I suggested, is the one that you can put on while its under water. Glad I could help.