Everyones right........however the only reason that HPS is better for flower is becasue it has more lumens per watt verse a MH......BUT MH can increase your potency.....MH gives off UVB rays which have showin to improve potency.......Alot of old timers like MH for flower becuase they are only concerned with Potency verse yield.......I do a mixture i run MH for veg then i switch to HPS for flower but then i switch back to MH the last 3 weeks of flower to add the UVB rays to my buds......
You ask, well dosent that make my yield smalller?? well not really because by the last 2-3 weeks my buds have pretty much grown as big as there going to get so at that point i can switch back to the MH and still not really affect my yield but i can inhance my potency.....Make sense??
This is why alot of outdoor growers will force there plants to flower early so they can utiliize all the UVB rays that the suns gives off in med summer.....If you dont force flower, your plants wouldnt flower tell fall and in fall you loose alot of the suns UVB rays.......This is why some despensary's will only buy outdoor if is forces flowerd early....
Heres another thing to consider Most of the UVB rays from a MH is blocked by the glass of the bulb and if you use an aircooled hood with glass then any left over UVB rays would most likely be blocked by the glass........So if your using glass in your hood you probably wouldnt benefit much from putting the MH bulb back in during the last 2-3 weeks of flower.....however the blue spectrums will still get through so using it for veg wether you have glass or not is usually a good idea.......make sense??
