Now that you've built your koi pond, what next?
Other than populating the pond with your kois, you first need to know the basics of maintaining good water quality in your pond.
It can't be emphasized well enough that kois need clear, well-aerated water to survive, thrive, and live happily ever after. The need for pond clarity is connected with koi appreciation: you can't enjoy what you can't see.
Regular schedules. Your pond water maintenance should include a regimen of regular cleaning and filtering. When you're able to see clear to the bottom of your pond (which must be at least 4 feet deep), then you know that your pond water is up to par. (Enthusiasts advise that pond water has to be as clear as to make the kois appear to be floating.)
One effective way to clean your pond is to change about 10-20% of the water monthly. Be aware though, that water needs to "mature" over some time before kois can live in them. You can also reduce the waste matter in your pond by cleaning up a few minutes after every feeding.
It's advisable to clean your koi pond thoroughly in spring and just before the onset of winter.
Equipment. You'll need tools to keep your pond spic and span. Your list of essential equipment should include water filters, water and air pumps, vacuums, waterproof electrical fittings, and hoses and connectors, among others.
The need for filtration can't be emphasized well enough. Kois eat almost anything. They can be fed up to 8 times daily so they can eat up to 2% of their body weight in a day. Imagine how much waste a large koi population can accumulate in a day!
You'll need an appropriate type of filter to strain out these and other waste materials in your koi pond. A good filter system should be able to take out as much solids as possible from the water. Remember the rule of thumb for good filter systems: the bigger it is, the better it works. Of course, its size should also be appropriate to your pond dimensions. It shouldn't be too small or too big.
You may also consider installing skimmers to trap larger-sized debris (like leaves) before they can sink beneath the surface. Skimmers are mechanical filters that work with pond filtration systems and are built to blend in with the aesthetics of pond designs.
Plants and other aquatic decorations. Kois can't be exposed to direct sunlight if they are to grow. They need the shade to survive, and you can provide a screen with the use of decorative plants and trees.
Overhanging foliage can screen off the sun but you have to continuously skim the surface for fallen leaves. Kois are bottom feeders and they may feed on decomposing leaves, stems and other similar gunk on the pond floor so it's essential that you take them out immediately.
Because kois were bred for appearance's sake, selective breeding has weakened their immune systems. Thus you need to clean, clean, and clean your koi pond so it will always be a healthy, viable environment for your pet kois. Besides, good water quality means total viewing pleasure for you and your kois' other audience.