Industry experts, including David Cochran, an aquatic biologist and owner of White Path Water gardens in Ellijay, GA., said the first and most important step for overwintering ponds begins in the fall with leaf removal. He said the easiest method is stretching a net across the pond to catch the leaves before they fall into the water.

Leaving plant debris in the pond over winter provides a starting place for bacterial infections in early spring, Cochran said. After all the leaves fall, he said to remove them and perform a thorough pond cleaning.

Once clean, pond experts recommended supplementing the pond with bacteria formulated for cold weather. Jeff Spillars, vice president of marketing for Winston Co. in Tulsa, Okla., said the ecosystem continues in cold weather and under ice. The bacteria removes algae as well as the fish feces and ammonia, he said.

Jack Colman, president of Clear Pond in Camarillo, Calif., recommended adding a laumontite crystal product in a bag. “It’s an all-natural mineral that helps reduce ammonia and increases oxygen levels,” he said. “Plus it is safe for fish to eat and improves their color.”

After owners clean and condition the pond, those living in colder climates need an aerator and de-icer, pond experts said. Aerators provide oxygen to the fish and deicers keep a hole in any ice that forms, Cochran said. A hole in the ice enables proper gas exchange and air flow, he said; otherwise the fish can die.

Cochran cautioned against breaking a hole in the ice with a sharp sudden impact because it shocks the fish and could kill them. Instead, he recommended running a deicer in the water all winter.

Derk Hebdon, owner of Bratt Water Features Inc., in American Fork, Utah, recommended that owners check their water features well in advance before it snows or freezes because waiting often can mean it is too late to fix the problem. For owners with a check-valve, which keeps water in the return line, Hebdon recommended turning off the power and draining the line around Thanksgiving, to prevent water from freezing and breaking the pipe.

“Don’t wait until after the ground is frozen to call us to winterize the feature,” Hebdon said. “Once the water has turned to ice inside the return line, there is a good chance it will stay that way all winter.”

Carrying the necessary equipment is part of Hebdon’s proactive checklist. He recommended buying a heater in the fall to avoid the rush after the first freeze. By that time pond businesses carry a minimal amount of inventory, he said.