i start with molassas as soon as they show sex. havent done a side by side comparison but i know when i started using it, about 3 years or so, i noticed a big difference shortly after applyig it to half my garden. i use soil and have never had any bad side effects that were due to mollassas. my garden is small 8-12 plnts of varying strains from both extremes, pure indica to pure sativa and in between. maybe i am just lucky but i am a firm believer in molassas.