The reason the roots aren't drowned in hydro is that you are keeping the water oxygenated either by bubbling it or by keeping it in constant motion. Or both.
When you over water soil plants, the water in the pot is mostly just standing there and not allowing air (oxygen) to the roots.
Go ahead and get your bubbler set up and give it a go...You'll be surprised how easy it is...About the only thing that you can really do wrong is over nute.
You gotta be pretty careful about the res. temp, But other than that it's a piece of cake!..........J