The optimum design is to have a pump circulating the pond water from the lowest level up to the top of the pond and allowing it to run down to the bottom of the pond. This assists greatly with aeration, the design has to be carefully planned to ensure that the levels are correct. Ponds have to be made sufficiently deep to ensure that there is enough depth to allow ducks to dive, which they enjoy doing. The ponds shown in the photo below consisted of a series of four ponds. These were constructed on flattish ground so soil taken from the lower ponds was used to raise the level of the other ponds.
The edges are held in place with sandbags and wire mesh is laid into the pond shape and held down with strong wire pegs. It is wise to place a few small stones here and there over the surface of the pond before laying the wire mesh to raise the mesh slightly here and there, which ensures that the mesh becomes embedded into the concrete as it is laid. Concrete is then mixed and laid into the pond. A final plaster coating containing waterproofing mix is applied to the pond surface. Ensure that the edges are not too high or sharp. At certain points the edge should be created with a gentle gradient slope with a scored surface consisting of shallow horizontal lines at these exit points to give the ducks traction when climbing out of the pond.
Before introducing ducks into your pond plant sufficient vegetation to give the ducks shade, but not too much as this makes them difficult to catch and view. Duck boxes must also be placed in the enclosure to allow ducks to nest. I this picture you can see pockets have been created to enable the planting of water plants here and there around the edge of the water.
While the vegetation is being planted fill the ponds and allow the water to circulate for a few days as this will allow the cement to cure and will also assist in removing any unwanted pollutants from the water.
When we started a collection of exotic ducks some years ago we decided to have a high density of ducks per pen area. In order to do this we realized that static pond water would soon became fouled and unsuitable. Emptying and refilling was not an option due to the periodic shortages of water (we have our own boreholes, but water from these has to be conserved in the dry season). It was essential to filter it in some way or other.
Research was started on the best method of doing this. The initial options we investigated were around the filters used in large koi fish farms, however, the start-up cost of this equipment exceeded what we were willing to expend. As a first attempt we constructed mechanical filters in large plastic drums where the water passed through plastic filter media. This is appropriate for smaller ponds but not for a larger ponds. It also had the disadvantage of having to remove the filters and clean them regularly.
Finally we designed and built a “natural” bio-filter system that consisted of a large trench dug into the ground in which a number of chambers were constructed; these were filled with coarse media such as rocks and stones or pre-washed rubble to a certain height and then filled with plants. A pump was placed in the last chamber of the filter and water pumped to the top of the series of ponds which lay at a slightly higher level than the bio-filter and gravity fed back to the pump.
The success of this method is dependent on a number of factors:
- The correct size of the filter trench in relation to the pond volume
- The selection of the correct filter medium
- Plants that would extract the duck excrement out of the water, and thrive on it
- Selection of the correct pump size
Once this was resolved we never looked back, and these filter trenches have been in use for the last three years and keep the water clear and clean. They also look good because of the plant growth. The picture above shows a bio-filter containing papyrus grass which grows prolifically and we have found that this plant provides the most efficient filtration system.
With this problem solved we expanded our duck pens and our exotic duck stock.
NOTE: The two viewing the pond are NOT part of our exotic duck stock but visitors that dropped by!