STEP 6: Installing The Liner 
Before installing the liner, make sure you have flattened the top of any perimeter soil berms. If you did not fill excavation with sand and/or carpet, make sure than any stones or other sharp objects have been removed. Rub your hands over the surface of the soil to make sure everything is smooth.
With a couple of people helping, the liner is unfolded into the excavation. It's best to do this with bare feet, or soft-soled shoes. The liner is then smoothed into place from the center-bottom up, and is lapped over the top edge of the pond 6 to 12 inches. A small amount of water is typically added to the bottom of the pond to weigh the liner down and help with the smoothing process. Folds in the liner, which will be necessary to help it conform to the curves of the pond sides, are incorporated as the liner is smoothed out.
STEP 7: Place The Pump. 
Place the submersible pump in the bottom of your pond (or in the cavern you built under the base rock of the waterfall). Attach tubing and drape over the waterfall foundation.
STEP 8: Install The Filter 
A filter is optional, however, if you want to keep your pond water clear and free from algae, a filter that contains a UV light is highly recommended. There are filters that you can place within your pond, or those that can be installed outside the pond. I like using the one's that go outside the pond. The filter will have an intake and an outflow. You will run a hose or tube from your pump to the inflow on the filter. Then you will run a a hose or tube from the outflow that will go to the top of your waterfall.
STEP 8: Install Any Interior Rocks 
Once the liner is in place, and your pump and filter have been installed, you may begin to add rocks or small boulders to the INTERIOR of the pond if desired. Rocks that will be placed beneath the water surface should be washed and scrubbed thoroughly to remove all dirt and other particles.
STEP 9: Add Water 
Now you can begin to add water! It could take some time to fill your pond with water using a garden hose. While the pond is filling, use the time to begin placing exterior rocks around the perimeter of you pond.
STEP 10: Placing Rock
Start by placing flat stones around the perimeter of your pond and the rocks that will serve as the base of your waterfall(s). Allow these flat stones to hang a little over the edge of where the water will be. Then place rocks or boulders of random size and shape atop the flat stones. Make sure the liner, pump and tubing for the waterfall are all in place. When the pond is full of water all thats left to do is turn on the pump!
