..I would like for more people to chime in with their opinions.
My gut is telling me that if you have enough flow through the 3 foot drain pipe to run a "contraption" capable of properly aerating a 1 acre pond that the benefits would be marginal at best. That's a lot of out flow which would be washing the aeration efforts right back out of the pond.
Now, building the contraption for doing something aesthetic like a water fall or fountain would be real cool, so I love the ideas.
If aeration is the goal, I would look at aerating the water as it is coming in. My gut still tells me that that would be hard to increase the O2 enough to make a difference IF you have high throughput. Do you have any idea how much water passes through the drain pipe?
A far as the Trompe is concerned...your friend's comment of a 70' fall has merit. 70 foot of water head yields 30psi...BUT, how big would the down pipe need to be to produce the volume of air needed to run at least 3 heads for a 1 acre pond?...that's a lot of air. I have not convinced myself that the head pressure would be 30 psi (70' of water at 0.43 lbs/foot), something about it having a lot of air bubbles that want to travel back up the tube makes me think that the resulting head pressure would be less. The diameter of the Trompe would need to be pretty big which would demand a lot of water flow... I've talked myself in a circle and have to ask why aerate water the will be flowing back out of the pond and being replaced by low DO spring water? If this is possible, the benefit would be minimal given the fish are doing fine now.
The above mumbo-jumbo is mostly opinion and gut feelings, but I would like to see some of the math if it can be produced.
