The bottom of the pond pictured is a gravel over pond liner installation. This is not the best or most effective surface. The waste and organic matter is hard to clean out of the rocks, After all of the heavy lifting and dirty work, it is nice to sit back, enjoy the view and relax.
This is a large water surface when it is full and up and running. The wild ducks love to sneak in each spring and try and set up nesting. Ducks and ponds really do not mix. At least pools without good filters. I spend many mornings chasing ducks out of the garden. A formal swimming pool is just a few step up the hill, I refuse to let the ducks into the swimming pool.
One year a hen hatched 7 ducklings out and they enjoyed the garden. Soon enough they found a way into the swimming pool. They could get in but not out of it. I made floating islands and stairs for the babies to leave the water.