MH and T5s has some burn in time requirement to get to their full power and spectrum. Don't quote me on this, but I think it's 100hrs. So if you run your light 8 hours a day, it'll take about 2 weeks.
I personally haven't had to acclimate anything due to my change of lighting. If you're worry, I would just hang it a couple inches higher than you'd like and drop it from there.
Again, I seriously think just the Radiums will do the job for the 180 and the T5s are not needed or just supplementing more blue/actinic for the color glow.
Ok that works. The t5 I'm doing for the color. Like you and others have said radiums will be more than enough.