T5s and bleaching LPS - anyone noticed this?

[Myka]

Navarchus, the corals mainly effected were all three types of brains I have (Symphyllia, Trachyphyllia, and Lobophyllia), Duncans, Hammers, and Frogspawns. The brains moreso than the others. I had to keep all of these near the bottom of the tank or they would bleach, they would start to bleach within a week even though polyp extension was good. Once the halides were on the tank all of these corals were placed within 12" of the halides for over a month, and didn't bleach out at all.

Oh come on now Steve, there is no issue, it's a discussion - just an oddity that I was wondering if anyone else shared similar experiences, or had any ideas as to why this would happen. The T5s were the exact same bulbs (as stated above), removed from one fixture put into the new one. One Fiji Purple and one AquaScience 17,500K. However, I noticed bleaching with all the other T5s I had tried in the last 2 years as well (Giesemann and Hagen). I suppose they had different reflectors and different ballasts running them, so there may have been a bit of a change there, but I would think not much. They went from a Hagen fixture to a Degenbao fixture.