i didnt see how big a tote your using, regardless, how close are they to each other with 4 in there. i use 14-18g totes and 4 in one for that strain...prob be ok at 3', there not really bushy. but for the scrog: id set the screen about a foot. there thin stalks, so you could prob do it sooner, but the height of the screen is dependent on if the stalk would snap or not. really you can set the screen now, just have to wait for it to grow tall enough to reach the next square. i havent though of a supercropped screen til now. it may be possible to pinch the stalk to kinda speed up getting it to the next square, but for the entire screen may harm the plant. you dont top at all in scrog. you simply run the plant up and down thru the screen. what happens is the plant gets the max light to all the bud sites, topping might make two heads but theyll prob yield the same, just smaller heads. oh, for the screen alot of people use that nylon or string net mesh they use for tomatos. ideally youd wait for the screen to fill in before switching, as its a sativa dom gene, it does have height growth advantages. changing the res depend on how you built it, or how it comes. i set mine up on some books with a drain on the bottom of the side. i have 8 site totes due to clones and you could prob just cut a hole and put a plug in it to fill it. forget taking the plant out and mixing nutes in the tote, youll have to do it in jugs.