Seriatopora Top Branches Bleached?

[RainboWBacoN420]

Hey all, I'm fairly new to the reef scene so I apologize for some noobness I may reek of, especially when it comes to SPS. Anyways, last night i did a water change as usual, for a while during the change, some of my birds nest branches were exposed out of water for about maybe ten minutes. After the change, I noticed the parts that were exposed, the polyps were not out, the branch still had its usual color. I passed this off as normal as they were probably stressed. Woke up this morning and noticed those same parts looked bleached! It looks completely dead... I have a feeling this is because of the AI: Hydra 26's I installed the other day. I think the intense light was too much for the exposed branches.... I'm not entirely sure, though....

What type of seriatopora I have, I'm not sure, it's a light orange base with white-tipped, almost transparent polyps, if that helps any..

 

[aaron23]

Pics would help, if anything it'll recover with good water parameters

 

[RainboWBacoN420]

Pics would help, if anything it'll recover with good water parameters

A poor quality pic, but it's the best i could capture under these darn lights.
See how the branch is bleached?

 

[aaron23]

I don't think the lights were the reason for the birdsnest to start receeding. Many times when I do water changes my corals are exposed to my lights. Just as corals are exposed to the sun when there is low tide they don't just receed. Have you checked your parameters?

 

[RainboWBacoN420]

I don't think the lights were the reason for the birdsnest to start receeding. Many times when I do water changes my corals are exposed to my lights. Just as corals are exposed to the sun when there is low tide they don't just receed. Have you checked your parameters?

I'm aware that corals get exposed to the sun, but the sun isn't 6 inches over the sea... that's why I think it's my lights and being exposed out of water for a period of time.
But my parameters are:
Alk: 9.3
Cal: 420 ppm
Mag: 1290 ppm
PO4: 0.10 ppm (working on it)
NO3: 10 ppm
Salinity: 1.025
Temp: 80°F

But the top branches deteriorated over night! They were thriving prior to the water change... and it's only the parts that were exposed, so I don't believe this is a situation with my parameters.