Use Rapid Rooters in place of the Rockwool. Rooters are 100% organic and can be used in Hydro or soil. RW can have problems with PH drift not to mention builds up salts and needs to be flushed on occasion. I used RW for over a year and now am on my 3rd grow with RR's instead and have had faster root delevopment from my clones, no sign of algae start on tops, a more constant PH between rez changes and not being forced to flush :jointsmile: