Its not really a question of time but intensity. You should find some way to slowly every couple off days to acclimate the corals. Some people raise the lights and slowly lower them to the proper level. Or you could use layers of windowscreen over the tank and remove each layer slowly. Use a sheet of eggrate to hold the screen above the tank.
The last method has worked for me in the past.
__________________
Sean
Back in the good ole days 
|