yes as soon as your water/nutes hit the rw it aborbs the juice up to the roots. I would put a 2 inch layer of hydroton in the plastic pots and lay your 2inch cube on top and fill sides with hydroton. just do not flood above the top layer or your hydroton will float out of place. Within a week or two your roots should start popping out of the bottom/sides of the plastic pot. Keep the ph between 5.5-6.0. Forget the 3 inch cubes they are not needed. the hydroton will keep your baby in place