I understand that when you replace mh bulbs you should reduce the time the lights are on for the first week. Is this true and how should the new lights best be phased in. I dont want to kill my corals!!
No need to acclimate the new bulb if you change the bulb on the recommended time. If you waited longer to change the bulb, then the bulb's spectrum starts to shift at a bigger ratio, then you need to acclimate the bulb. I would start off with half of the regular lighting period and increase it by a hour every few days until you reach your normal lighting period.
