If you have ever kept a fishbowl or an aquarium tank, chances are that the time will come when you start thinking about a koi pond. Perhaps you have been amazed by the koi ponds kept at Buddhist monasteries in Japan, where these ornamental fish symbolize all the positive aspects of friendship, perseverance, and good luck.
Building and keeping a garden pond with koi and other species are not overly difficult tasks; they just require more work and take longer than a freshwater aquarium tank. Although some landscaping companies offer garden pond services that include establishing the ecosystem and even stocking the pond with koi fish, this is the kind of project that can be very fulfilling when completed on a do-it-yourself (DIY) basis. Elizabeth Hurley has a beautiful pond that you can use as inspiration.
Pond Site Selection and Planning
Since building a garden pond is something that will likely require digging in the ground, you will probably need to be a homeowner; otherwise, if you are a tenant, you will have to get written permission from the landlord. The best spot will be close enough to the house for the purpose of getting a view from the interior and not just when you are in the garden.
You will want to look for a spot that gets at least a few hours of shade during the hottest months of the year. Even though koi are resilient aquatic species, they descend from the Asian carp that swims in colder waters. Too much direct sunlight may create algae bloom problems.
The next step is to trace where the pond will go on the ground. Here you will have to remember that the smallest pond, one that will hold two koi, will need a volume of at least 1,500 gallons. If you can make it 2,000 gallons and at least a couple of feet deep, even better.
Think about the potential of an above-ground pond. When you look at pictures of elaborate garden ponds complete with plants and rocks, you may not realize that many of them are pre-formed ponds that are partially set above the ground. Pre-formed shapes are often better than digging deep and trying to fit pond liner material to hold the water. Even if you choose to dig a ground-level pond, seriously consider a pre-formed shape made of fiberglass; this is what the professionals often recommend.
Start getting what you will need in terms of the aeration system, the pond filter, the biological media in which nitrobacter colonies will form, and the substrate along with anchor rocks. If your project will include a waterfall, might as well get it now.
Pond and Substrate Placement
After digging the hole for either the liner material or the preferred pre-formed shape, take a look around to figure out how much room you will have to feed the pond species and clean the pond. Once the liner or shape is in place, make room for the filter and lay out the substrate; if you are using liner, you will need heavier rocks to anchor it in place. At any rate, larger rocks provide a diversion for koi and other species.
Plan out how the filter will connect to the aeration pump and waterfall system if you will include one. Test that the connections fit properly and will not leak. Now you are ready to place rocks around the pond and fill it with water.
Establishing Pond Water and the Nitrogen Cycle
Once you fill out the pond with water and test the pump system, immediately start adding the chemicals to eliminate chlorine and to promote bacterial growth. After a couple of days, you will want to start adding plants; ideally a mix of floating and rooting species. Once the plants start taking hold and growing, you will want to check ammonia levels to ensure that nitrobacter colonies are forming.
Even after adding bottled bacteria, it may take about six weeks before a full nitrogen cycle is complete and you can stock the pond with koi. If you want to reduce this waiting time by a half, ask your local koi breeder to give you a few gallons of established pond water to transfer to your pond. When you do this, get some common goldfish, the large ones and not the smaller fancy kind, and let them stimulate bacterial bloom for about three days before doing a final ammonia level check and stocking with koi.