HPS is warm lighting, red spectrum. Aids in bud formation & trichrome production. Causes stretching, elongated stem growth. MH is cool lighting from the blue spectrum. Encourages healthy leaf growth, short stong stems & plant respiration. HPS in vegetative growth can cause long enternodes, weaker stretched stems that sometimes can't hold the bud weight, & a much taller plant that may out reach your grow areas height. You end up with much more stem & a spindly plant. If you have a choice, DON'T use any WARM light for vegetative growth.
catbuds Reviewed by catbuds on . Which is Better, 400w MH or 600w HPS During Veg. Stage I have a 600 digital ballast that can run 25%, 50%, 75% or 100% power. Question, which provides better growth during veg. stage, a 400w MH bulb, or 600w HPS bulb? My hydro store guy doesn't sell a 600w MH, he said most people use a 600w HPS during veg and flower stages. Thanks for your advice. Peace, PIF:thumbsup: Rating: 5