Ideal pond clarity should be between 18 and 24 inches. Having a “darker” pond will limit the vegetation in the middle because of the limited sunlight reaching the bottom. However, clarity of less than 18 inches can cause the phytoplankton (onecelled organisms that make the water greenish) to die off causing lack of oxygen in the water. This lack of oxygen can kill everything living in the pond.

A Secchi disk may be used (or made) to measure the clarity at various depths by drilling a hole thr...