Would I be better to just be using the 600w or is it a waste of power when I can use the 400 MH
Hi Kiwipaulie
My understanding is that the blue spectrum of a MH light will keep your internode spacing nice and tight, so they don't stretch too tall during veg.
HPS has more red spectrum of light, which the plants use in the flowering process - and the extra wattage will make a significant difference too in terms of your final yield.
These represent the sun's light during the year - it's cooler/bluer earlier in the season, and redder towards the end.
I guess you have to decide what is more important - your energy bill, or your final yield.
If it was me, I would flower under the HPS all day long.
To my knowledge, it depends on your priorities. MH grown bud is sometimes considered to have a better aroma and flavor, while HPS grown bud will win in the weight department. In a perfect situation, you might be able to take advantage of both bulbs and their corresponding advantage.
In terms of aroma quality, I have never done a side by side test with identical genetics, but I'd be very interested if anyone else has any opinions on the matter.
Peace
MM
