2x 600 growlux
8 in 25ltr buckets
sooooooo many factors
Good genetics (most important),co2, humidity (very important IMHO), 80-85 temp day 68-72 night (little or no fluctuation), fresh air at night (no added co2), PROPER bulbs!, heated water, accurate PH, correct nutes (not too much!) & lots of TLC. unless you have the perfect set up that can be trusted to maintain that type of regime on its own you need to check your room/plants frequently! Once you see stress you have already fucked up so like everything in life this wonderful hobby takes time. effort, LOTS of reading & lots of fuck ups but when you get things dialed there is alot of satifaction in watching a room of plants all growing like maniacs!!
I grow in coco and find that to be the most forgiving substrate.
I am certainly no expert but I did & still do take good advice & also try new stuff all the time to try to 'hone' my horticulturalist skills!!