How to Keep a Pond Clean & Clear

No matter how large or how few fish live in them, ponds can get dirty quickly.
All ponds need routine maintenace, no matter their size.All ponds need routine maintenace, no matter their size.
The water can become cloudy, green or even stagnant. Stagnant pond water not only has a bad odor, but also is a potential breeding ground for biting insects like mosquitoes. Regular pond maintenance can help keep the water clean and clear. Pond maintenance tips are the same for any type of pond, whether it is for commercial fish farming, for swimming or to raise large domestic fish like koi, according to Cornell University.

Step 1

Check for the cause of any cloudy water. Scoop pond water up with a clean, clear glass jar. Put the jar of pond water in sunlight for 4 to 5 days. Algae will move about constantly in the water and will turn the sides of the jars green or brown. Silt will all settle at the bottom of the jar and will not move about.

Step 2

Treat the pond for excess silt. Throw in 100 lbs. of hay to treat silt caused by clay soils. Treat a pond with hay no more than five times a year, treating as needed. For other types of soil, add agricultural lime or agricultural gypsum as the manufacturer suggests.

Step 3

Check the sides of ponds for erosion, which could add silt to the pond water. Mammals like muskrats or beaver will cause holes or crumbling sides. Repair the sides of the pond with tight-fitting rocks like rock rip-rap or fencing that does not rust. The rocks or fencing will discourage animals from digging. Hire a pond contractor to do the work if necessary.

Step 4

Remove excess leaves and pond weeds with a pond skimmer or rake. Rotting leaves or weeds can cause the pond water to turn brown and cause a large buildup of ammonia that can be fatal to any fish or creatures living in the pond water. Rotting leaves and weeds can also help trigger a population explosion of algae. Taking leaves off of the pond’s surface is enough. Digging to the bottom of the pond is not necessary.

Things You Will Need

  • Clean jar made of clear glass
  • 100 lbs. of hay bales or agricultural gypsum or agricultural lime
  • Pile of tight-fitting rocks or non-rusting fencing
  • Skimmer or rake

About the Author

Rena Sherwood is a writer and Peter Gabriel fan who has lived in America and England. She has studied animals most of her life through direct observation and maintaining a personal library about pets. She has earned an associate degree in liberal arts from Delaware County Community College and a bachelor's degree in English from Millersville University.