What types of aerators have been considered?
In one of our shallow, purpose built marron ponds (area, 1000 m2 ), a paddlewheel aerator (~ $1000) is run briefly three times a day on mains power; this aeration is necessary to offset the oxygen demand of a high rate of daily feeding and allows crayfish production at about five times that of a farm dam. Farm dams don’t have mains power, so use of wind and solar power are obvious possibilities. The problem with windmills supplying power directly (no battery storage) is lack of wind when you need the power to mix dams during summer. We are currently researching the industry suggestion of a single solar panel unit ($400) operating a small aquarium pump to circulate surface water to mid-level in a dam. One of our suggestions has been for a farmer to visit dams once a week during midafternoon and mix each in turn for about 20 minutes or so with a big outboard motor or a paddlewheel on a tractor power take-off. This method needs to be trialled.
