I haven't used rock wool before but I imagine clay balls would be similar. are you running a recirculating pump between res and pot? If so set your res lower than the pot so it can drain back, if not you want them level so you can tell the water level in pot when you look in resivour should be the same. Then you want to do a trial run, you want a few inches gap between the bottom of the basket and the water level to start with, have it all running for 1/2 hour and check that the levels staying the same if using pump it can get a bit tricky specially if pot draining slower than pump is pumping resivour, adjust res/pot height if needed. Secondly you want to see moisture on the bottom of the basket from when the air bubbles are popping on the surface and water droplets are making it onto the basket. You will need to top feed until roots are visible out bottom of the basket.. some people lower water level over the growth of the plant but I'd get started and then look into that at around week 4 of vege.. after you have roots showing, avoid lifting basket out of pot, every time light hits the roots its damaging them, same as light hitting the water, also you risk twisting the roots up if you keep moving them around, resulting in root rot etc.
hopefully someone else can correct any errors Ive said and can tell you about the Rockwool side of it. Sounds like you're excited 😆
