Can you open the hood and place the lights higher off the water? It sounds like the corals may be in shock. You could try using just one bulb and then adding the second one later (as in a couple of weeks). That way you stagger the times you will make bulb replacements which should help the corals acclimate to the new bulbs.

A quick tip. Use a Marks-a-lot (permanent marker) and write the date on bulb when it is replaced. That way you will know how long it has been in there and give you an idea of when it needs to be changed.