HOW TO MAINTAIN POND WATER QUALITY?
WEDC provide a factsheet on Improving Pond Water. Its basic advice is to reduce contamination by restricting activities around the pond, stopping any use of the pond for washing / cattle drinking, and building platforms so that people do not have to walk into the water. It also recommends a simple filtration system to improve the quality of water drawn from the pond. Don suggested using a native species of duckweed to remove nutrients, adding that it also shades the water so helps to keep other growth down.
