While pool liners have similar material makeup to pond liners, they are not ideal for pond liners. In reality, pool liners may seem cheaper than pond liners but they are actually more expensive if you do the math. While pond liners are cheaper per square foot than pool liners, pond liners are at least 15 mils thick and thicker liners are always recommended. Pool liners are about 20 mils thick. When you buy a pond liner, you always buy 2 feet wider and longer than the intended hole so you can bury the liner all the way around the hole. With a pool liner, because it is sold at half the width of a liner, you always have to buy 4 feet wider and longer than the hole. Therefore, with a pool liner you are buying twice as much material or half of what you purchase actually lines your pond. So while a pool liner is only 2 mils thicker, you purchase actually double the amount of material; more than double the cost. Therefore, pool liners are more expensive than pond liners.
Additionally, pool liners are simply not made for the purpose of being a pond liner. Pool liners are designed to hold chlorinated or brominated water. Chlorinated or brominated water will kill almost all organisms in a pond. The whole point of a pond is to hold live fish and plants, many which are very delicate.
