http://groups.yahoo.com/group/pulserpump/ gives more info (in the files and photo pages too. It is related to the fish killer but It is probably benificial to fish in most climates. The fish killer is a deep tromp which dilivers pressurised air to 50 feet or much more deep. This can give fish the bends from disolved nitrogen. A pulser pump like what I have made goes less than 10 feet deep. Nitrogen disolving in water is mostly related to the time the bubbles are in contact with the water and the pressure and to a lesser extent to the temperature of the water. (Cold water absorbs better). I believe that pulser pumps will normally be benificial to fish because they oxygenate and because they remove quite a lot of odour producing chemicals from the water. (I welcome any research to verify this).
I do not think my site will disappear just yet. It has been online for about 5 years and I encourage people to copy it (as long as they acknowelege my work).
I also encourage people to make models and pumps and send pics or emails to me with their results. (The response so far has been extremely dissapointing).
There is work to be done on pulser pumps and on syphon pumps.
You might just enter the science history books if you do it and publish first.
If you have a plastics company, or indeed any company engaged in work in 3rd world countrys, it might be seriously good publicity if you researched the pump and published your work.
I do not believe it is worth the work and money that people spend converting low head hydro to electricity. It is probably cheaper and more efficient and much more environmentally friendly to instead use the energy locally for direct pumping and the other uses discribed on my pages.
Best of luck with your research
Brian White