if it were me,Id avoid layers but thats me broseph. I have always had lesser luck predominantly with layering techniques. being middle layer might work a lil better,but id mix it all together IMO I would take said mix you make up,and use that in the initial soil amount for said size of the pot and mix it together. what I would do though is use a top coating. or rather MAKE a top coating and let it blend until your ready to use it in a handful of weeks for flower.