I am going to be switching from my combined wattage of 212 flouros (2 red spec, 2 blue spec), to a 600w hps during my 3rd to 4th week of flowering. I am wondering if it will cause any stress to the plants. I guess i'll be making the switch anyway but I always check my decision-making with GC . Please state if your reply is an opinion or if it is commonly known that the plant does... such and such.
All your plants will do is love you for the switch. Just keep an eye on the temps, because the hps will run a lot hotter than the fluoros.......
Let us know how she responds, i'm interested coz i can't say i've ever changed the conditions for a plant half way through flower like that, even though i may have fair experience shifting plants from flouros to a 600 during veg. I'm not much of a punter but i bet it'll grow massive roots real quick and bud like a mother fucker. If it dies i bet its coz of heat, whether it be at the root zone or burn up top, so don't fuck that one up or it'll be your fault! One thing i've noticed is a plant (only a vegging one in my experience sorry) moved from a flouro or two, to a 600... suddenly requires a stronger nutrient solution, quickly showing signs of light green new growth. When i put plants under the 600, for some reason, i hang the light pretty high till i'm satisfied that the plant is comfortable. Like, when it's not droopy and has nice dark green new growth. Watch the roots take off (if you can see 'em, dunno your system), once she starts receiving more photons! And we all know more energy means more growth!