getting ready to flower

Getting ready to switch over to 12/12

Picstures here in my grow journal https://www.rollitup.org/t/found-a-seed-planted-it-and-now-here-i-am.877167/


Should I switch from my MH to HPS for a few days before i switch to 12/12 or can I just go ahead and change lights and let it roll?

Thanks