tinytoon- Why would you not recommend rock wool??

I use it with consistent results. Id recommend it most for this system as it makes for a shockless transplant and its super easy to clean. They get watered once for about 10 mins a day. I grow my clones completely through their veggie stage in the rockwool; then when I go to flower I transplant the rockwool into buckets with expanded clay pebbles on a multiflow bucket system. Works like a charm!!