Hi! I am new to this forum and to the pre formed pond thing. I was wondering if anyone could help me with how to keep rocks somewhat in place on the sides of the pond. I don't like all that black showing, and I would like to cover them with rock.Some have told me I could use insulating foam, or liquid nails. I do have fish so it has to be safe for them. Any suggestions would be greatly appreciated. Thanks so much!!!!