If you are new to Koi, it can difficult to determine how to pick the best Koi for your pond. Before choosing the fish, however, you should have your pond in place with a good filtration system already working before putting any fish in it. You should also have any plants in place before you put the Koi in the pond. The reason is that planting aquatic plants kicks up much loose dirt and debris. Such debris can be detrimental to the health of the fish.
It is probably best to use a layer of gravel in the bottom of the pond to anchor the roots of the aquatic plants. Before planting, rinse the roots off with water to keep as much dirt out of the pond as possible. Check with various sources to determine the ideal plants for your Koi pond. Some recommend no aquatic plant whatsoever, because the Koi eat the plants. However, if you choose the right kinds of plants, they can actually help the Koi. Plants provide shade and a place to hide from predators.
Certain plants, such as watercress, can actually help filter the water, keeping it clean and crystal clear. The cleaner the water, the better it is for your Koi fish. Koi may kill off certain types of aquatic plants by eating them, but the Koi will not be able to eat watercress fast enough to kill it. In fact, you may have to thin the watercress occasionally to help keep it from growing too fast and overrunning the pond.
The water conditions should be just right before you place any Koi in the pond. Since Koi are so expensive, perhaps costing hundreds of dollars per fish, first put a few inexpensive goldfish in the pond to see how they fare before introducing the Koi to the water.
If you really want to learn from Koi specialists, you can always take a trip to Japan and visit the breeders. Japan is where Koi were first bred and raised. However, since the price of touring Japan may be beyond the means of many, you should at least visit a few local specialists. You might be able to find a pet shop with a Koi or two for sale, but you will probably have a better chance of getting healthy Koi if you purchase them from a Koi specialist. You ought to check out a few places and learn all you can about the various types of Koi before you buy any. That way you will know what to look for and which variety you prefer.