I agree with
@gmslave, leave the mh bulb in unless you want them to stretch, sometimes I do this on short Indica phenos that I want to encourage stretch or I leave the mh bulb in on Sativa or stretchy plants that I want to restrict the height on. Also I would leave the veg feed in for the first 5-7 days.
Again I agree with recommendation to not use the 24hrs darkness route as I found no difference when I have tried it but some claim finishing a few days earlier.