After laying all the liner (if you have one), place the pump in the lowest part of the stream or pond, setting it on bricks so it won't take in silt.
The pump should be set opposite a waterfall, if you have one. At this location the pump provides maximum circulation and aeration.
Attach the pump to the supply and outlet lines. Turn on the pump to move water through the pond. Allow any header pools, terraces and catch basins to fill, settling the liner into place. Fill the pool halfway, readjust the liner then let the pond fill completely. Make sure that no liner will show after the edging is installed. Add or remove soil beneath the liner to bring the edge level with the water. Trim the liner if necessary, but leave enough to go under the edging. Make the final trim after the stones are set in place.