yeah i actually came across an college experiment that was done using three types of plants wheat and a bean ect, the results showed that the soil in this case actualyl grew better but then they mentioned that the hydro setup was infested with beetles and i noticed that they talked about salt build-up, i mean maybe if they refined the experiment a little more like no bugs and a flush say every few days of straight water that woudl be better, who knows i love to hear everyones comment so KEEP COMMENTING!!! Here's a few links that were sent to me...just a decent read to get the mind thinking..

http://www.cannabisculture.com/articles/2374.html
http://www.southwestern.edu/academic.../05/000205.php
http://www.growingedge.com/magazine/...hp3?AID=170555


GG23