Combined with the skimmer increasing water clarity, it is getting more light than it did before. The new bulbs were probably double the PAR of the old ones...maybe even more.

How many T5 bulbs is your fixture? When I ran T5's I would only change one or two at a time to provide a chance for everything to acclimate. I took a sharpie marker and put the in service date on the end of them so I knew how old each bulb was.

My guess is your candy cane will make it...the top part maybe not. It should be easy enough to frag that part off and you will still have a nice piece. If there is still some flesh visible, it can come back.