Hi David. From what I understand, there is no difference between hydroponic (water) roots and soil roots. Give this PDF a look. It seems the difference is the oxygen content along with the regular flow of nutrients that makes the difference...see what you think. I do know that cuttings started in water have roots that are a bit finer and need time to acclimate to soil, so usually need a little extra moisture when transplanted. I hope these links are of help to you.
http://osufacts.okstate.edu/do...
According to this info, you can use any rooting hormone, but liquid and gel, like Clonex are just easier to use.
http://www.simplyhydro.com/cut...
