If say for very serious cases, another alternative that I can think of is to remove all your corals to a temporary tank for 2 weeks. Then black out the main tank with the fishes inside (Just turn on blue light for them - they don't need strong lights anyway). Shift your main lightings to the temporary tank where the corals are for the time being.
The above mentioned is only meant for short term solution. Keeping bioload low, as what the other reefers have mentioned earlier, is still the best way to go.