Effects of too much light or old bulbs?

[Madmak]

Just curious as I have a couple used 6' fixtures above my tank and want to be sure I recognize a problem early.

My 12 bulb T5 light has all new bulbs. My 3X150W (20K) Halide plus 4X96W PC (Actinic) light has used bulbs.

My controller ramps them up to a high noon effect and back down (by number of bulbs, not percentage). I thought my T5 fixture wasn't bright enough so added the Halide/PC fixture later.

Back to the question, what are the effects of too much light or old bulbs? I have no experience with this...

[sphelps]

Too much light - bleached corals, lower light LPS and soft corals may also shrivel up. Typically with proper acclimation not an issue.

Old bulbs - Obviously lower light output for one, shift in spectrum which can cause more algae growth depending on the bulbs. Color can also suffer and if old bulbs are changed out all at once you can shock the corals.

[Reef Puffer]

i have a small tank. i had 4 h0 t5 bulbs. i switched out two bulbs for a 150w hqi with pc's. the hqi is an old bulb. one month later red cyno EVERYWHERE. loose the old halides IMO!! other than online i cant find new bulbs anywhere either... just my luck tho.