PRE-FORMED POND
You have the choice between pre-formed pools or pond liner for your pond. Both have their advantages.Pre-formed pools made of Polyethylene (PE) or glass fibre reinforced plastic (GFK) are particularly durable and relatively easy to install. However, they do impose restrictions on the design because even large one-part models often offer less than 10 sq.metres (100 square feet) water surface and the depth is usually a maximum of 80 cm. This is not enough for fish to over-winter in it.
Larger pre-formed pools that need to be assembled from individual parts are often awkward to handle and, of course, they too cannot be arranged according to your personal taste. Nevertheless, a few accessories could give you a certain freedom for your pond design.
By adding a natural looking stream to your pre-formed pond , you could enhance the overall appearance of your pond.