How to get bigger autos

I found out once I stopped trying to hard my autos got alot bigger if I don't tip them they can get over 6 foot tall. I tip them at the 6th set of branches then leave them alone . I personally use a minimum of 27 litre lots with just using Yates seed raising mix and powerfeed bottled fertilizer. I also recommend trace elements folar feeding feeding it gives the plants a boost. Hers a pic of my gorilla cookies auto 10.5 ounces dry . Cheers bob