When installing the pond, you should use a two -layer film with a thickness of 500 mK. But this option will be fragile, since this film is easy to break if there is a mechanical effect or in large frosts, it is not a stand against the effects of ultraviolet rays.
PVC film will be more expensive and more stable, but it has a number of disadvantages that are similar to the shortcomings of the polyethylene film.
