i prefer 18/6, 24/0 for the prevegitative stage is best tho (thats the 1-2 weeks the sprout grows befor leafes and nodes start growing) it keeps it shorter and stronger, also helps root developement enourmously and thats most important durring sprouting. but like i said after the plant has a few nodes and leaves i like to take it to 18/6, this makes it grow more, marijuana grows roots and stores energy in them durring the day when they can make food. at night when they cant make food they use the food they srored all day to build the plant. so the plant itself grows at night.