| There are many different types of filters available | | | | The most common filters are the up-flow, |
| today for koi ponds which require regular cleaning. | | | | down-flow, submersible, recycling and pressurized |
| The decaying fish waste and pond debris need to | | | | types. The most common problem plaguing the |
| be removed from the filter, flushed and cleaned | | | | operation of any filter is channeling. Water will |
| with a garden hose - a labor intensive, stinky, | | | | always take the path of least resistance. Filters |
| filthy, disgusting job if there ever was one! | | | | use a variety of filter media or material for the |
| Biological filters are designed to filter out | | | | water to pass through. Pond water contains a |
| particulate and organic substances. By utilizing | | | | large amount of suspended matter that collects in |
| anaerobic bacteria-laden filter media, a bio-filter | | | | this filter media, eventually blocking or plugging the |
| breaks down harmful toxic substances into | | | | spaces between the material. As this occurs, the |
| harmless by-products. Busy koi ponds without a | | | | water will divert to another available path until it, |
| bio-filter will develop an environment harmful to its | | | | too, clogs. Eventually, the water flow will find a |
| inhabitants as a result of the build-up of fish | | | | permanent channel, avoiding the filtration process |
| waste, decaying pond creatures and leaves and | | | | altogether until the media is removed, cleaned and |
| other debris that have settled to the bottom. | | | | replaced. |
| The size of the bio-filter used in a koi pond is in | | | | In the case of a down-flow filter, it operates on |
| direct proportion to the number of fish per gallon. | | | | the principle of gravity, as opposed to pressure or |
| The more fish, the more waste and the bigger | | | | up-flow. So when the media begin to clog, gravity |
| the filter that is needed. Do you really need a | | | | is not sufficient to force the water through the |
| filter? Not necessarily on the small ones -- not if | | | | available channel at the same rate that water is |
| you follow nature's guidelines. Natural lakes and | | | | being pumped through, so it spills out the overflow |
| ponds don't have mechanical bio-filters and they | | | | drain back into the koi pond, unfiltered. |
| are home to many healthy fish. | | | | The most efficient and maintenance-free filters |
| If, however, the koi fish begin to overpopulate | | | | are pressurized filters that have a backwash |
| the lake and start running out of food, they would | | | | feature. A bio-filter contains filter media on which |
| thin out naturally until the population was small | | | | nitrifying bacteria reside, and which break down |
| enough to be sustainable by their environment. | | | | the toxic nitrites into less toxic nitrates that can |
| Such a hypothetical overpopulation would cause an | | | | be used by the water plants. Consequently, the |
| imbalance in the nitrogen cycle by producing too | | | | more surfaces that are available per square |
| much nitrite from the koi fish waste. Then the | | | | centimeter of material, the more effective the |
| increased pH of the water would create an algae | | | | filter. |
| bloom that could fill the lake and choke off the koi | | | | Recent technology developed by Aqua Ultraviolet |
| fish. | | | | produces special hexagonal beads for their |
| Man-made koi ponds can be controlled | | | | pressurized filters, which possess the greatest |
| mechanically and chemically to allow for larger | | | | maximum available surface area of all existing |
| numbers of koi fish per gallon than would be | | | | filter media. They are tapered so that the beads |
| found in nature. Many formulas exist for dictating | | | | are less likely to group together. Back washing |
| the proper number of koi fish a pond can hold, | | | | forces water through the filter in the opposite |
| whether you calculate koi fish per square surface | | | | direction, breaking loose solid material and flushing |
| foot, koi fish per cubic foot, koi fish per gallon, | | | | it free down the drain outlet. Or, with the use of |
| pounds per gallon, or pounds per cubic foot. The | | | | a flexible ribbed hose, it will direct the nitrogen-rich |
| bottom line here is: healthy water equals healthy | | | | waste-water onto the lawn, trees or flowers. |
| koi fish. If your water is fish-friendly, the number | | | | Maintenance involves a simple turn of handle for |
| is insignificant, within reason. | | | | about one to two minutes. |
| If the air were pure, and if you had plenty of | | | | Down-flow or upflow and submersible filters |
| food and water, and a healthy way to eliminate, | | | | require disassembling and washing of all enclosed |
| you could live in a small house with 30 other | | | | media, and then returning it to the filter -- a very |
| people and stay reasonably healthy, were it not | | | | messy and dirty process. Unfortunately, |
| for one thing: stress. Koi fish are like humans in | | | | pressurized back-washable filters are costly and |
| that respect. If it gets too crowded, the koi fish | | | | are designed for larger projects for use with |
| will try to leave the koi pond and some actually | | | | out-of-pond pumps which are needed to |
| do, but they do not get far. If koi fish are | | | | adequately back-wash the filter. Thus, it is |
| jumping out of a koi pond, it is not because they | | | | necessary to settle for the high maintenance, less |
| have an exploring nature; the koi pond is either | | | | effective down-flow or up-flow filters for smaller |
| too crowded or the quality of the water is less | | | | koi ponds of up to 300 gallons. If you are one of |
| than desirable. | | | | those people who now have, or are thinking about |
| FILTER TECHNOLOGY | | | | building a small koi pond, I have great news for |
| Man-made devices stretch the natural parameters | | | | you! Twenty-five years ago when I started in this |
| set by nature, allowing the koi pond to support | | | | business, there were few small pond filters |
| more life than it normally would. The biological | | | | available. However, with the advent of the liner |
| filtering system is the best way to accomplish | | | | pond in the early nineties, everybody and his |
| this. The more advanced the technology, the | | | | brother-in-law started manufacturing down-flow |
| more effective its ability to treat water. There | | | | filters in their garage. With no marketing plan, |
| are as many different types and configurations of | | | | capital, or quality craftsmanship, most all the |
| filters as there are people wanting to get rich off | | | | fly-by-night-by-the-seat-of their-pants back alley |
| manufacturing and marketing their own filters. | | | | filter hopefuls faded out. |
| Almost every koi pond or water gardening | | | | A filter for a 250 gallon koi pond will range from |
| magazine contains more advertisements for filters | | | | $160-$200; for a 1000 gallon koi pond, $300-$400; |
| than any other product. Which one is the best? | | | | and for a 2000 gallon koi pond filter from |
| First, let's discuss the various types that are | | | | $500-$600. Happy koi, peace & joy. |
| available. | | | | |