HELP! From 2 T5's to 6 acclimation

I have my corals under 2 x 6500k T5's everything looks really healthy but I'm adding four more bulbs. ATL Blue + and Purple +'s. how should I do this so as not to shock the creeps?

 

You can add one new bulb once a week or once every 2 weeks to be really safe.

 

You can add all of the bulbs and cut back the light period to 4 hours and add an hour every week or two depending on how the corals react.

 

Thanks. I can't add a bulb at a time so I'll cut back to four hours. and turn up every week.