what glue to use in pond water

[Len1948]

what glue/adhesive should I use to glue some rocks in my 500 gallon yard pond?

[genocidex]

what do you mean glue rocks? aquarium safe silicon is the best bet tho. idk any good brands as i only buy it at my lfs but theres some in homedepot if you look.

[bignellm]

Marine Grade Epoxy or Silicone. The Silicone would give you more time to work, before it completely adheres and dries.

Usually can find in most hardware stores.

[smaug]

Depending on where you are talking about placing them,having rocks in a pond is not always advisable.Due to the harsh outside environment scaping in this way is not very good for long term durability.

[dbosman]

Concrete for that size space. But...
Only if you live in an area with no hard freezes.

[Furface]

In the cold climate where I live, there probably is no glue that will hold reliably. Temperature changes, freezing and thawing around the pond keeps things shifting slightly and sooner or later the stones will pop lose. Especially if water is involved, with it's shrinking and expanding. Smooth stones, laid against the slope in my pond have worked well for many years. Even a couple of small ponds that freeze solid in winter I have overlaid the liner with grapefruit sized smooth stones and the cracks filled with pea gravel stay nice. They operate with just an aerator and plants, no filter. Just a couple of fish that mostly feed themselves with bugs and algae that make sure no mosquito larvae survive. The fish come out in the autumn.