hi i tried it ,about five weeks into flowering,only cos i read something on the net,by the three little birds,some organic growers who seem to know what they are talking about,about the same amount as brutus,i dont know if it improved anything,but the weed was fucking nice,and it did not cause any problems,and i grow d.w.c so i was a bit worried,so give it a go,i now use it on my outside dope,it as it is a carbo boost which is a lot cheaper than the carbo stuff you would buy from a hydro shop,nothing ventured ,nothing gained as they say.