Energy-less Pond Circulation

I'm doing a pool to pond conversion for a friend. I've got the fish (pluckies and goldies). I threw in a few lilies. Things should mostly require time, patience, and fine-tuning to equalize the ecosystem and provide a human food source. Now, I know it's not REALLY necessary, but they have a pool waterfall that would be so aesthetically pleasant to have run occasionally. Sure, we could get a massive pump and circulate the whole thing. But, we're against wasting energy, so we want to do it with basically zero energy cost. Oh, and for as little $$ as possible. Any ideas?

I have a small pond with a fountain for aeration that uses a 60 watt solar panel, linear current booster, and 12v submersible bilge pump. It works great and is a great demo for solar PV. You can shade the panel with your hand and watch the fountain slow down. It also provides automatic compensation for the need for aeration. More sun= warmer water=lower dissolved O2= faster pumping, more O2

Thanks Phillip, for the suggestion. I have to say though, I'm not a big fan of solar panels -especially for pumps. Solar panel pumps require converting solar energy to electric energy to mechanical energy - which is really a lot of energy loss through transformation. Sure, it doesn't seem like anything because you only have to pay for the initial system set-up. But, then again...it takes a whole lot of energy to manufacture a pump and a solar panel.

Sorry to be so difficult, but I'm trying to buck that system. I like wind better than solar (easier to design and fix), but the pond is surrounded by trees and a house, so it doesn't get much air movement.

I only know of creating thermo syphon's by shading one end of a pond and opening the other end up to the light. But that's water circulation, I get the impression your asking if water can travel uphill for free.

Breaking the surface tension of the pond adds considerable oxygen to the water. A very light windmill of some sort could turn something like a rake to skim the surface of the water. I don't know how much o2 this will add, but it will add to it. By breaking the surface tension, you are creating edge between water and air.

There you go Saybian! http://www.youtube.com/watch?NR=1&feature=fvwp&v=uzJ-TvcaeR0 ...almost like pumping water up hill for free! Lucky for me this project is in Southern California where we get plenty of sun and very little cold, so this should work perfectly. Budget wise, it's also pretty cheap and easy to make.

Additionally, Yukkuri, I might add a light windmill to add to the circulation.

Thanks!

Yarrrr! sounds like a thermo syphon is what you were looking for, it's not gushing waterfall but yeah even without shade some black pipe vs a blue pool should create enough temperature differential to get your water moving. When I think of shading one end of a pond and lighting the other I was thinking such large scale circulation I didn't really think it would apply so simplistically to trickle circulation which is plenty with a little bit of splash to keep a poolpond oxygenated. I live in the canadian pnw so sunny days are only about 35% of the year but yeah california pretty much guarantee's this will be up and pumping 95% of the time. It will most likely even work on those 7 days of rain most of cali get's all rear.

Wind. Alter your landscaping to get some airflow across the pond.