There are two types of ponds: those constructed from a preformed shell, and those with a "freeform," flexible liner. You can be creative with either type, and you can also join multiple ponds together with waterfalls and streams.
Flexible PVC liners allow you to build ponds in shapes and styles that suit your taste. They're easy to install since they conform to the shape you've created. Flexible liners are suitable for ponds from 50 gallons to 1,500 gallons. For larger ponds, liners can be joined together with a sealing tape. Your local pond retailer can help you select the right materials.
Preformed ponds come in several popular shapes, ranging in capacity from 9 gallons to 270 gallons. You can find many different sizes and shapes of these ponds at your local pond/DIY store.
To calculate pond volume: Length ___ ft. x Width ___ ft. x Average Depth ____ ft. x 7.5 = gallons
Next Video - Step 3: Choose your pond filtration