[coral reefer]

In my opinion he is a little extreme in his guidance! Yes he/she is correct in the whole thing of acclimating corals to new bulbs or increased lighting. However, corals will show signs of stress due to the stronger lighting, increased PAR/PUR. Polyps don't fully extend or open up as well as possible bleaching, but these occur infrequently and not at the stop of a dime unless in extreme cases. In my opinion, it is best to turn your old set of lights on first, then after a couple hours, turn the new set of lights on for a couple hours, then shut them off then after another hour or so, turn off the first lights you turned on. Turn actinics on first and last before nighttime.
That is the best way to do it with as little stress as possible to your corals, anemones and clams.