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). The Swell HDPE Pond Liner 25-Year Guarantee is one of our best-selling pond liners. These garden pond liners are made from a flexible 0.35mm-thick HDPE (high density polyethylene) material that, while not quite as thick as rubber pond liners, is similarly durable. It's also UV resistant and, when paired with protective underlay (sold separately), forms a great base for a quality pond. We stock 20 different sizes of these flexible pond liners, from small pond liners measuring 2.5x2.5m to large pond liners measuring 30x40m. These garden pond liners are easy to fit, whether they're small pond liners or large pond liners. Their HDPE make-up makes them flexible pond liners that are well suited to a wildlife pond or sculpted garden ponds like Koi ponds. They also create a great seal, keeping pond water where it should be - in your pond! Our heavy duty liners are incredibly durable and built to stand the test of time. In fact, we're so confident in the durablity of these fish pond liners, and the HDPE they're made of, that we've given them a 25-year guarantee. This 25-year guarantee covers your pond liner against damage from sunlight. It doesn't, however, cover damage from punctures so it's highly recommended that you lay down a layer of protective underlay prior to installing your pond liner.