Koi ponds are all the rage for homeowners these days. There is nothing like relaxing at the waters edge while feeding a writhing school of koi or goldfish as they fight for every last scrap of Purina fish chow. It kind of makes you feel like a benevolent despot with your own little fiefdom of fishy peasants. But lets be honest, this is the kind of landscaping project that often winds up with a pond full of dead fish. How can you keep your swimming serfs in good health?
Koi and goldfish ponds need periodic maintenance so the waters chemical balance stays within the range that allows fish to thrive. A heater may be necessary to keep the pond at proper temperatures. Plants that help clean the water are always a welcome addition since they supplement the filtration system. Waterfalls or fountains help keep oxygen levels high. Clear water is important it lets you actually see the fish you spent so much money on.
If the water is healthy but still murky, make a window. With a raised pond, you can seal a large piece of thick Plexiglas along the side. This lets you see the fish lurking at the bottom. Its not SeaWorld, but it works!
Bridges, plants, overhanging rocks, or decorative structures can be placed in, over, or near the pond to create shade for 50% or more of the surface. This is a requirement for the health of your fish and gives them places to hide from backyard predators.
Sunny areas are also necessary. You need to strike a good balance between the two. When you are planning your pond, mark out the area. Watch how the shadows and light move across it over the course of a day. This will help you figure out where to place your pond shade structures and plants for maximum effect.