Few things are better at taking the edge off a rough day than relaxing to the sound of running water while watching brightly colored koi darting around a pond. These distinctive fish are members of the carp
family and in Japanese culture they symbolize love, friendship, strength and courage. Symbolism aside, sturdy koi can provide a unique, dynamic aesthetic for decades and are priced accordingly: A 6-inch koi can cost $50 or more.
Ponds should be placed where they can be viewed from inside the house or enjoyed from a patio or deck. Ideally the site should receive about four to six hours of direct sunlight per day. Providing shade from the harsh, late afternoon sun will keep the pond from overheating in summer and restricting the amount of direct sunlight helps keep algae in check.
“Build the pond as large as you can,” said Demi Fortuna, owner of August Moon Designs, a pond and water feature design and installation firm based in Stony Brook. Fortuna is also the director of product information for Atlantic Water Gardens based in Mantua, Ohio. “Clients often say that they wish they had built their pond bigger. But no matter who does the building, make sure the contractor or the homeowner calls 811 before digging. That’s the national one-call number that connects to the local utility. It will prevent excavation in an area where there are buried utility lines.”
In addition to the square footage of the pond’s surface, consider the depth and volume. Here is where pond design turns into a balancing act. Koi aficionados say that ideally, the fish should swim in a 36-inch-deep pond. But a pond deeper than 18 inches is considered a swimming pool by most building codes, which means it needs to be placed in a yard surrounded by a non-climbable fence with self-latching gates. Fortunately, 18 inches is safe enough for the koi, provided there is no overcrowding. Fortuna suggests a water-to-fish ratio of 10 gallons of water for every inch of fish.
Raccoons and some birds can wipe out any fishpond in no time. The sides of the pond should go straight down to discourage these predators from jumping in. Deeper ponds should have a flat shelf 18 inches below the water level—a measure of safety should someone fall in. A shelf at that depth is also a nice spot to place oxygen producing container plants like cattails, lotuses and irises.
The pumps and filters that keep the water clean and the fish healthy will be sized by how much water needs to be serviced. The equipment should be able to circulate the total volume of water every hour. And because the equipment operates continuously until winter, energy usage can become a concern. “High-efficiency asynchronous hybrid magnetic drive pumps cost two to three times more than utility pumps, but they save that in electrical costs in a few months,” said Fortuna.
Manufacturers sell complete pond kits that include the rubberized pond-grade liner, pump, skimmer, waterfall and all the fittings needed to match the pond’s size. DIY kits start at about $1,700 for an 11- by 16-foot design. Once the pond is running it requires maintenance to keep the fish fed, the plants trimmed and an eye on algae bloom and mosquitoes. Come winter when the water temperature drops below 55 degrees the koi become dormant. There is no need to feed them because they will survive on their fat reserves. Should the pond freeze over, poke a hole in the ice to allow oxygen in and carbon dioxide and ammonia to escape.