Question
I bought a preformed pond at Home Depot but need to know if it is made of polyethelene.  I want to use pond foam to attach a waterfall made from a small pond liner to the preformed pond.  The pond foam says it won't work on polyethelene.  Could you please tell me what the preformed ponds are made of?

Answer
Hi there!

I think that those ponds are made out of PVC plastic(polyvinylchloride)

Why don't you do a little test?
Use a fine sand paper so that the surface of the preformed pond will adhere better to the foam. Stick a piece of the liner to it and see the result.

Good Luck!

Carlo