Root exelurator in the first 3 weeks of flowering, then you use something like a bud xl till the end.... then you would add a boster half way in .. then you would use a finishing nutrient like: shooting powder, or topshooter the last 3 weeks of flowering
I would recommend going on coco, but buy a ph pen & ec pen, make sure they test em in the shop, yoi dont want false readings
* also buy a small mini fan or two, so you can blast them with air, make sure they get fresh air non stop, helps them get bigger faster..
* Than a sticky environment. *
i would go with 2 litre pots for 40 plants under 600w, or maybe 30... idk. nah i would do 35.
or if you want less you need to get bigger pots, and veg longer.. LST THEM !