No, dcw setups have nothing to do with drippers. Dunno what ur hydro guy was tellin u. Ur rockwool will get wet through the rocks, which get wet from the popping of the bubbles at the water level. u do need to make sure this happens by adjusting ur water level at a good position. Hydroton is very good at displacing water even if there is no top feed. Just to make sure u could mist the rockwool everyday to make sure its getting wet. rockwool is good for this becuase it holds alot of water for a reletivly longer period of time compared to grow rocks. so having them def. helps. gl hope this helps