For crying out loud, people. You cannot do hydro or soilless without some way of measuring PH. You shouldn't even try it in soil. A digital PH pen is $20 and a regular dumb-ass kit is about $6. Do not buy rockwool, nutrients, a fan, a ballast, or any other damn thing until you have a PH pen or test kit figured into your budget and are committed to purchasing one soon.

What the hell, am I in the twilight zone over here? Newbies, listen to this and listen good: Attempting a hydro grow with some way to test PH is analogous to saying, "Gee I really need to get to that place within the next 30 minutes. That place is 35 minutes away by car. There's no possible way that I could come up with a car at this point, but what the hell. I think I'll put a whole bunch of effort into it anyway."

Good luck with that, and don't come crying to me with your problems if you try it.