Another from Vatican city? What're the odds

The "general" rule of thumb is MH for VEG, HPS for flower. This is not a hard and fast rule though, just a guideline. I know growers who use MH alone all the way through and swear by it, and others who use HPS all the way through and swear by it. With all the different enhanced spectrum bulbs, and cfls and everything that are available, its hard to say theres a rule

I personally have found that using both MH and HPS through all stages enhances growth positively in a number of ways..