Been looking for this info and kept finding you in all the threads i have seen so i figured just asking you, just got a dwc 35 gallon bin, wanted to transplant five seedlings from soil to hydroton, just rinse roots off then place in hydroton??? Plain tap water for how long??? Aslo the bin did not come w/a drain plug, maybe cuz of the size, was wondering do i buy another pump to empty every time i drain the bin to put fresh water in???....how often are you supposed to change the water???