First of all I am not a clone expert but I do create lots of clones. I have to let the rock wool dry mostly out between waterings or I get green and black mold on top. My clone box has one 4' double flouride and no fan. It is about 4 1/2' Long x 14" H x 12" W. The clones still grow pretty good. I soak the rockwool in tap water the initial soaking. From then on I use the Clonex solution for new clones. As soon as I see any roots they go straight into FF Happy Frog. Hope this helps.