When changing bulbs or changing lighting!!!!!!!!


Staff member
RC Mod
First, if you are simply replacing an MH or other strong bulb with the same kind: start with a 4 hour photoperiod, adding half an hour a day. Some also use a temporary shield of gardening sunshield fabric. Corals take time to adjust: their internal algae have to divide and multiply. THey may have adapted to lower power while your bulb was burning 'down'. Now that it's 'up' ---give them a break from the sun, as you wouldn't rush out without sunscreen, having flown from winter to the tropics, or you'll fry.

When changing types of lighting: assess how old the bulb(s) you've been using is/are. And compare potency. If you think this/these new bulb(s) may be more powerful, err on the side of caution and give them that gradual ramp-up.

Corals can take total lights-out for days on end---3 days off is a routine treatment to remove cyanobacteria. LIke a storm on the reef.

But one hour of unshielded radiation they're not prepared for can really hurt.

Dark doesn't hurt them any time soon. Too intense light can wound them in an hour. Take precautions. Go slow. They may be wonderful lights---but let the corals slowly build up their internal 'tan' of flora to be able to benefit from them.