Fish ponds, like any other household project, come with a myriad of concerns. Chiefly, the hardware must be strong and long-lasting while the living things in contact with the project must be safe from harm. For fish ponds, the lining, plumbing and accessories must be sealed and adhered in place properly with products that will not harm the fish. Failure to purchase a quality adhesive can lead to repeated repairs and fish replacement, both of which can cost a lot of money.
Epoxy adhesive, even when every attempt has been made to provide for the safety of the fish in a pond, cannot be guaranteed for the well being of all aquatic life. Mr. Sticky's Premium Adhesives has gone through the trouble of having their products pass a test specified by the California Department of Fish and Game's regulations, but they warn they cannot guarantee complete safety of aquatic life. If their product is used, strict adherence to the instructions must be followed to replicate the testing that verified the product to be safe.
Silicon is an adhesive and sealant that is controversial as a glue for fish bonds. There are products deemed to be 100 percent safe while other products claim no type of silicon is safe. The CT1 Company claims silicon will break down with continued contact with water. They do not keep a secure hold and the breakdown releases solvents detrimental to fish. Other silicon products claim to be food grade and therefore safe for fish, or they claim their product is simply 100 percent safe for fish, provided they are allowed to cure for 24 hours before being submerged in water.
Solvents are toxic for fish. However, they can be used as a vinyl liner adhesive as long as an appropriate drying time is used. Once a pool has been drained, Boxer Adhesives recommends a glue that has a curing time of two days, or in cooler temperatures four to five days.
Hybrid formula polymer adhesives developed without solvents or other volatile organic components are non-toxic and less harmful to the environment. These adhesives are considered to be food safe while having extremely strong bonding properties. They will bond with rubber pond liners, stone, concrete, wood and plastic.