New MH install, how to adapt corals

[smalltimer]

If you will look at my set up below, you will see my current lighting, I have ordered a 250 watt HQI that will mount in the top of canopy, 5 inches off h2o, only the lens of the bottom of the fixture sticks into the canopy, so the heat is dissapated though the cover on the top. I have about 15 or so corals, from hydrophora, to leather, mushrooms, should I use some sort of screen or will running the mh like 4 hrs, one week then move up slowly to 10 hrs. do the trick...........Please let me know if anyone has had experence with same,
Thanks

 

[wamp]

When I changed to MH from VHO, I lowered the corals in the tank and slowly moved them back toward the top.