i know it stand for high pressure sodium so dont worry about that
but i still need to know what its best for flowering, veg or what the spectrum specifcations on hps and if its good enough use all the time.

i also was wondering what height of a plant is it best to start flowering,
and if you have a plant in veg and the light period is 12/12 will it force flowering on the young plants and if the preflowers are visable and you change the photoperiod to 20/4 will this harm the plant or cause the buds to form at an early age or what?