Almost 3 weeks ago, I received 2 new MH
bulbs from one of our sponsors, I had previously been using a Ushio 10K, but was not real pleased with the decrease in spectrum over the course of the year I ran it. It started out very white/blue and by the end of the year was pretty darn yellow. I was changing brands, from Ushio to CoralVue, I wasn't sure what spectrum I wanted to get so I got a 10K and a 20K, the sponsor was out of 10Ks so they sent me a 12K and a 20K and promised to ship the 10K when it was in, I could send the one (or two) I didn't want back. I got the bulbs and added the 20K bulb to the system, I was off the next day and had every intention of finding the extra set of pegs to my timer (good reson for digital timers), the new bulb ran for a couple hours the first night, the next day I received a call from the school at 8:15am telling me my son had probably broken his arm, we went and got him and spent the next couple of days in the hospital (not only did he break it, he broke it pretty bad, had to put it back together in the OR), needless to say, my reeftank was the last thing on my mind. In total the reef got 1 full (9.5 hrs) photoperiod and about 6 hours of the next day before I was able to get the pegs for the timer and set up a reduced schedule. That was all it took. I am currently using the 10K and have had to further slow the acclimation due to all the increased UV
of the new bulb. I looked at the spectral analysis of the CoralVue 10K bulb and it is actually an 11K and has quite a bit of UV
in it. At any rate here are a couple of pics to show you why even if your simply increasing the spectrum of the bulb (less intense) you should still adhere to a good photo-acclimation.
I don't have a before of this one, but the damage is obvious.
There are two other zo colonies that are effected and my star polyps aren't happy (that really isn't such a bad thing). From the after zo pic above you can see it is the polyps in direct light that are effected the most/worste, the ones on the left are in indirect light and have pretty much kept their color. The bleaching areas on the Pocillipora are all in direct light.