Pond kits are the quickest and easiest way to build a professional-looking pond in your backyard - especially for beginner water gardeners. Pond kits include the all of the basic equipment and instructions needed to build and maintain a garden pond. Pond kits typically include a liner, underlayment, aquafalls, and a pump and silicone sealer. Kits with more complex or specialized pond equipment will be more expensive. More expensive and complete pond kits include every imaginable piece of equipment you'll need to get started - such as pond skimmers, starter bacteria and dechlorinator, Koi food and even a pond thermometer. Pond kits usually cost anywhere from $500 to $1,700 online.