Waterfalls are one of the most popular design elements in a koi pond. Waterfalls increase aeration as well as enhance the sound and look of your koi pond. There are many ways to design your waterfall. One of the best methods is to use a waterfall weir that easily attaches to the liner. Even on a natural rock waterfall or stream, having a weir at the top allows for even distribution of the water. This improves aeration as well as the look and sound of the waterfall. There are many designs and styles above that are open for review. Some have built in filtration, other are simple chambers. All of them have been used an reviewed by your peers so you can make the best choice!