Oh yeah, they're working on roots the entire grow man, it may slow down root development later on, but as long as there is room to go they will continue to do it. I get that you're eager but you may want to consider a couple soil grows before you go into hydro. When you make a mistake in soil there is a pretty decent buffer the soil affords, with hydro you have no buffer so if you get something wrong in terms of PH/EC, etc you can go from happy plant to dead plant in a very short period of time. I'm not trying to generally discourage you, but you should try to set yourself for as little horror and disappointment as possible to keep your motivation up