just found the local hydroponic store and have some question (rookie first grow)

ok so im towards the end of my first grow and it went ok never goes perfect from what ive read. I am 3 weeks into flowering Florecent grow and was wondering what is the best nutrient to add at the end to fatten them up allitle more befor there hung.
also if you would like to tell me all the nutes you use with feedback would be apreciated. Im thinking "Cha Ching"

Did you want to use organic or not?