did you start with 18/6 then go from 12/12 and now you want to go back/?? you shouldnt start 12/12 unless its clones or low ryder....low ryder is a new strain that goes straight into flowering and only grow about 1-1.5ft tall...great for low key grows... you shouldnt put it back from 12/12 to 18/6 just leave it at 12/12 and the plant should pull thouugh