DAM! they look healthy , good job. and yea some people do the 24hr dark period when switching to 12/12, i dont see too much of the point but then again never done it.
o yea i missed the pic, but those look like some good nutes i saw them in a grow magazine but your the first person ive seen using them. have you used them before?
their looking good and healthy, well except for the one but again check the plant problem threads it will help you out but to me it looks like overwater
well MH bulbs are for veg but can be used for flower too as long as you switch to 12/12, but HPS bulbs work way better for flowering and will give you more yield