Build the perfect pond with the Swell HDPE Pond Liner – one of the most reliable, affordable, and easy-to-install solutions for garden ponds of all shapes and sizes. Made from high-density polyethylene (HDPE) at 0.35mm thickness, this durable liner is designed to withstand UV rays and chemical exposure, offering long-lasting performance for up to 25 years when installed with a protective underlay (sold separately). This is Swell UK's most popular pond liner.