When fertilizing lawns, keep the fertilizer a few feet from
the waterline. It will make it's way to the edge. High nutrition loads are the main cause
of algae growth.
If feeding fish in your fish pond, only feed enough food that
the fish will consume the food in 15 minutes. Excess food only adds more nutrients into
the pond.
Try to keep grass clippings from entering the pond. Discharge
the clippings away from the water.