Keeping a pond clean should be one of the first priorities for new koi pond owners. The easiest way to do this is with a pond bottom drain. More efficient than a submersible pump, pond bottom drains draw and filter out fish waste and other degrading matter, which can accumulate over time, obscuring the clarity of the water. Having koi in your pond can be enjoyable, but because of the amount of waste they produce, it will be a constant effort to keep your pond clean without a drain at the bottom of your pond to eliminate the waste. Goldfish also produce waste, but not near as much as Koi can. Not only do Koi produce more waste they also will grow bigger and faster then goldfish which will produce even more waste. The minimal effort and maintenance required over the long term makes it desirable to have one of these for keeping a pond clean, circulating the pond water around the clock.
Installing a koi pond bottom drain is the most difficult part of owning one of these bottom drains, but it won't be that difficult. Following the manufacturer's directions, the liner should be glued in place and all the proper hoses should be attached. A trench should be dug so the pvc will not interfere with the smoothness of the inside of the pond. The most important thing to remember is to have a proper seal when putting the pond drain in place, as this will keep the pond from leaking. Leaking ponds are one of the biggest reasons why some fear to buy bottom drains for their ponds, but in actuality, bottom drains are the least problematic filters when it comes to the possibility of losing water. When properly installed, they provide many years of drainage, usually going to a skimmer filtering out waste, leaves, twigs, and other solid matter and debris while maintaining the water level.
If you are in the beginning stages of constructing your koi pond, you are at a unique advantage for putting in a bottom drain. However, existing ponds can also be fitted with bottom drains, but the water must first be emptied, and there must be room at the bottom of the pond for fitting the rubber liner, as well as access to the drainage hoses if they are already installed, or room for them if they are not yet installed. A good bottom drain will last for the lifetime of the pond, and it will do its job at least as good and or better then a solids handling submersible pump, and without the aesthetic drawbacks.