| Pond Shape | | | | Aeration means adding air to the water to |
| The sides of the pond should 90 degrees, going | | | | increase the level of oxygen in the water; an air |
| straight down, to reduce access by predators. | | | | pump is the standard method of aerating the |
| The bottom should be 4' - 10' deep and the size | | | | water. The beneficial bacteria that keep the water |
| recommended is at least 1000 gallons; larger is | | | | healthy need oxygen to thrive. In general, you |
| better. | | | | need 40lpm of air per 1000 gallons of water. |
| | | | The primary time that aeration is needed is during |
| Filters | | | | the summer. The reason is that as temperature |
| Cost, maintenance, water quality and stability, and | | | | increases, water can hold less oxygen. In addition, |
| capacity are key factors in determining the type | | | | respiration rates of plants and animals increase |
| of filter to use. The two basic choices are | | | | during the summer, also increasing the need for |
| between a pressurized filter and a multiple | | | | aeration. |
| chamber filter. A head-to-head comparison for a | | | | One caution: The air pump should never be |
| 3000-gallon pond reveals significant advantages | | | | installed below the water level unless it has a |
| for a multiple chamber filter. | | | | check valve in the line. Otherwise, you will end up |
| Although the equipment costs for the multiple | | | | with serious maintenance problems. |
| chamber filter are slightly more ($2475 vs $2425 | | | | UV-Filters |
| for a pressurized filter), maintenance, capacity, | | | | UV-filters are used to kill algae and some disease |
| and water quality and stability clearly give the | | | | bacteria or viruses. Algae cells generally cannot be |
| advantage to the multiple chamber filter. Electric | | | | stopped by conventional physical filters; by passing |
| costs for the multiple chamber filter are | | | | them through UV light, their internal structures are |
| approximately half, regular maintenance is | | | | disrupted. The cells then clump together and can |
| approximately a fourth, UV costs are about half, | | | | be trapped and broken down by the filter. |
| and yearly maintenance is less. Further, the | | | | Generally, 8-10 watts of UV filter per 1,000 |
| pressurized filter provides inconsistent water | | | | gallons is recommended. |
| quality and stability compared to the multiple | | | | Housing for the pond UV filter may be needed in |
| chamber filter. | | | | the winter to be sure that the frost doesn't break |
| Filter media can be used singly or combined with | | | | the bulb; alternatively, the bulb may be removed |
| finer and finer filtration. Generally, media should be | | | | during portions of the winter. |
| used that will maintain favorable bacteria as the | | | | Amount of Fish |
| bacteria act in concert with the filter media to | | | | Show quality koi fish need 1000 to 2000 gallons |
| maintain a healthy water environment. | | | | per fish; for "regular" koi fish, 100 gallons per foot |
| Pumps | | | | of fish should be adequate. |
| In order to compute the size of pump needed for | | | | Installation of Pump and Filter System |
| your pond, you will need to determine the gallons | | | | The above components need to be balanced and |
| of water in your pond. You can compute the | | | | coordinated with each other in a good koi pond |
| gallons of water in your pond yourself by | | | | design. A simple design would be to make the |
| multiplying the average width by the average | | | | pond oval so that water circulation is easy. Have |
| length by the average depth to get cubic feet. | | | | at least two water jets coming out of the walls |
| Multiply cubic feet by 7.481 to get the number of | | | | to move the water in a gentle, circular motion. |
| gallons in your pond. | | | | For an even simpler design, pump the water |
| You need a minimum of half capacity in your | | | | above the pond and have it fall back into the |
| pump compared to the size of the pond. For | | | | pond in a waterfall. The bio-filter(s) and pump |
| example, if your pond has 5,000 gallons, you need | | | | would be placed at the top of the waterfall. The |
| a pump and filter with a 2,500 gph capacity to | | | | waterfall would act as an aerator for the water. |
| provide a turn over once every 2 hours. A | | | | This design would also provide easy access to the |
| turn-over of 1 1/2 time per hour is preferred. | | | | pump and filters for regular maintenance. |
| Pond Aeration | | | | |