Too much light bad for fish?

[cofstl411]

I have a 125 Gallon tank with two 6 ft. actinic bulbs and 3 250 metal halides. I usually only run the actinics for about 6 hours a day. I just used my metal halides for a couple hours. When I turned them out and went back to just the actinics my fish seemed to act strange. They were huddling together and darting about in a small area. Will a change like that stress them out? I have been reading that the actinics are cosmetic and for my viewing. What type of schedule should I use. I don't have any corals.

I can't believe the difference in the appearance of the fish with the metal halides on. The colors on my fish are so vibrant.

[charlie]

Is that the first time you had done that? I believe a sudden change like that will cause fish to "stress" ,if that is the first time that has happened. I have all my halides on timers so that the turn off is more gradual, and the fish will get used to the impending darkness.

[TROY182]

I would set them up to come on seperately then go out seperately. that way you can simulate sun rise , noon sun and sunset.