My memory is getting refreshed. I agree with Sue and Amanda that the partial aeration run time per day will be most beneficial if the run time is in one block instead of on-off cycles - preferrably at late day, night or toward early morning. I prefer to start mixing later in the day after the daylight (sun) has had time to stimulate photosynthesis which results in high DO in the upper water (euphotic zone). Then mix this high DO water to deep areas of the pond.
This is my rationale for mixing time: When the aerator starts, it progressively begins to circulate the water starting from the diffuser as an upward boil, then at the surface it spreads outward toward the edges. This denser water then at the edges, moves downward following the contour of the bottom toward the diffusers where it again flows upward. As this occurs and the longer the aerator runs, more and more of the 'middle zone water' gets incorporated into the circulation until the whole pond is 'mixing'. If the aerator only runs a short time (less than or just one complete circulation) very little 'middle water' gets involved or mixed. The longer the aerator runs the more the middle water is mixed. Remember - all this becomes more important the older and more eutrophic a water body becomes. Wind action will also affect the overall mixing. Not a lot of studies have been conducted on this entire topic which is what makes Amanda's work so interesting and informative. Good job Vertex! G1Fiddle - Since your pond is fairly new feel, free to experiment and learn from those tests. Keep us informed about your tests!
Last edited by Bill Cody; 04/22/11 11:17 AM.
