I gauge the quality of the water by the buildup of algae in the pond and in the spillway. The spillway makes a great water quality indicator. When there are excess nutrients in the pond, algae forms in the spillway. At one point the rocks in the spillway were completely covered with green and brown algae. But it cleared and now all the rocks are visible again.
Additional plumbing is planned in the form of a drain valve ahead of the spillway.
The drain would shunt the return water allowing the pond level to be lowered easily. Top Pond Pictures Larger version of picture at the top of the page. The pond as seen from the patio looking toward the gazebo. The pond as seen from the gazebo looking toward the house. This material is Copyright 1997 Craig Buchanan.