The benifits I see with rockwool, is it's easier to use, cleaner and it doesn't grow mold and fungus like soil. The nutrients also get to the plant more efficiently. I'm sure soil would work fine though.
Thank you for the info. The reason I ask about the soil is because that is what I already have setup. I want to grow it emersed, I just didn't know the best way to do it. Also wanted to know if you are putting any ferts in your water.