just consider your elec. bill | |
running both lamps at once will be more expensive. ideally you should run both at once, but personally i would stick to using just the MH for vegging and the HPS for flowering. of course, i don't have a dual ballast. if you've got it, go for it, its what you bought it for anyway, right - to run both at the same time. if you haven't bought it yet (which is the case as I see) i would go for a switchable system (throw a switch and switch bulbs). at least go for an HPS (or MH) system and get a conversion MH (or HPS) bulb. but you probably knew all this already... just my opinion, nothing more.
as far as improvements over running both instead of just one during vegging and flowering i can't help you- there are SO many growing conditions, i don't know if anyone can give a definative answer as to the level of improvement you can expect, but i believe that running MH and HPS at the same time is better. |