KOI PONDS

Koi are prodigious waste producers, and koi enthusiasts like to keep large numbers of fish in small spaces. A koi pond must be designed to facilitate the rapid removal of fish waste from the bottom of the pond, so it should have relatively steep side walls and a smooth bottom that slopes gradually to a bottom drain. A depth of 30" to 36" is adequate, except in severe climates.

In the illustration, a concrete collar is poured in a level trench around the pond so that the top of the concrete is about 6" below the desired pond level. A pit is built to hold the filter and pump equipment. The pond is then excavated; Liner Protection Fabric is laid over the soil and collar; and the fabric is covered with a Butyl rubber pond liner. Partially submerged rocks, laid without mortar, form the finished edge and conceal the rubber liner.

Waste-laden water flows from a bottom drain to a vortex pre-filter that settles out solids. An external pump then conveys the water through a bead filter designed to provide biological filtration for heavy fish loads, through a UV Sterilizer (not shown) that kills any remaining algae and prevents the spread of disease, and finally into a small pond (left) filled with water hyacinths and other fast-growing pond plants that extract any remaining nutrients.

Vortex Filter Systems: Gravity-fed vortex systems have always been the filters of choice for koi ponds because they gently draw pond waste into the filter in the form of solid matter that can be effectively separated, unlike typical pond filtration systems that macerate solids with rapidly spinning impellers before they reach the filter. Our vortex systems are particularly effective at solids separation because of their unique inlet design. Since the vortex filter must be positioned a few inches lower than the water surface of the pond, it must be either be installed in a pit or in a downhill location. A UV sterilizer is recommended but not essential unless the pond is heavily stocked.

Bead Filter Systems: Bead filter systems make superb koi pond filters because they offer high biological treatment capacity in a very small space. An external pump draws water from the pond and forces it through the filter and a UV sterilizer. The pump and bead filter can be positioned either above or below the water surface of the pond, and the water can be drawn either through a bottom drain or over the pond edge. We can gang together large bead filters to treat ponds of any size.

Combination Systems: Configurations that use both vortex and bead filters can benefit from the the best features of both technologies. In the example illustrated above, reliability is assured by the use of four different types of water treatment: solids separation in a vortex pre-filter, biological decomposition in a bead filter, disinfection in a UV sterilizer (not shown), and final clarification in a plant pond. A vigorous waterfall assures effective aeration, and a skimmer can be added to keep the water surface clear. The vortex must be either be installed in a pit or in a downhill location, but the bead filter and UV can be installed anywhere.