Article - KOI or Plants
Choosing Koi or plants for your pond
When planning a water feature, many of us will imagine water lilies, lotus, cattails, and things like that. Then we think of putting koi in there. You couldn't make more of a mistake if you added milk and cereal to the pond.
The different requirements are not even subtle. The plants require full sun, the koi need shade, at least part shade. The plants need calm water; the fish will do well in calm or fast moving water, the more filtration the better. The plants like to be left alone. The fish won't ever leave them alone. What do you really want as a water feature?
Let's look at water gardens: here is a piece of serenity, nature, easy to care for, and it will evolve over time. The water plants may be planted in a soil-bottom or set in pots on the bottom of the pond. There are a myriad of water plants and shallow-water plants, bog plants that would thrive in a sunny location with little or no care. They will invite a multitude of fauna to habituate your garden: frogs, newts, snakes, birds, butterflies, and all types of insects. There are fish that are perfectly suited to this type of garden pond without disturbing the plants. (Koi are not one of them.) Another beautiful thing about this type pond is no (or little) filtration is necessary. It will establish its own ecosystem in time.
The down side of water gardens is that they will become over-established in time and may need to be weeded out. Plants in water tend to grow much faster than those in the garden soil. They also develop enormous root systems making it difficult to separate or divide when the time comes. A natural pond will support this type of growth. A pond with a liner bottom will be easier to maintain and probably not as large, therefore should be more manageable. Some of the more aggressive plants would be Lotus and native species of water lilies. I also wouldn't plant any tall cattails as they will crowd out all other plants in a short period of time. Planting in pots would be the easiest to manage.
Koi ponds on the other hand will be a high maintenance operation, no plants, and expensive fish. It is heavy filtration, special feed, careful husbandry, and water changes. There is very little to resemble the water garden other than the water. We will get into koi later, but for now, just know that there are major differences in these two gardens and decide which you really like before you add the fish.