Is mainlinig vegetable surah enough?

i'd shoot for 3 colas per sq ft... get them spread out and leveled out, then let it go vertically -- that's when i'd flip to flower when it is leveled out, organized and ready to grow vertically. if you stick to 3 colas per sq ft it won't be overcrowded and if spread out evenly, it will fill the space fully. when you go from 18h to 12h, yes you need proportionally more power. Hopefully they are running at 2/3rds power or less and you can simply amp up the light without changing anything else. these are things that should be mapped out before you start. The plant can absorbe the same DLI in vege as it does in flower. With 2/3rds the hours (18-12) you need 150% of the power. this is why i said i hope it's ~67% power in vege... simply go up to 100% power and you are set for 12hours of operation. (if you don't run 18h, do the appropriate math... it's 'inversely' proportional to hours of operation).