open brain question

[sucram]

My open brain coral hasn't been "inflating" as much lately as it used to. It used to get big and fat, but now is almost always shrunken. It gets bigger when the lights are off, and then shrinks in size as the day goes on. If my parameters are all within normal limits, what is going on? Has this happened to anyone else?
Then:

 

[sucram]

Now:

 

[sucram]

Its in the same spot it was when I got it over a year ago, and I haven't made any changes to the water flow. I've been running 4x96 watt PC's since before I got it, and there hasn't been any color change in the coral. Any other ideas?

 

[alti]

sucram,
both my red and green brains have been doing the same thing the last few weeks. all other corals are fine and all tank params are the same. i did upgrade to MH, but it was doing this before the change. the only 2 things ive noticed that are different are the temp and the alk. ive been adding a little more b-ionic to the tank and the alk shot up to about 15 dkh. i was on vacation for 20 days and when i got back the temp was about 75. these are the only 2 things that seem a little out of the norm for my tank. there is no tissue recession at all, but they dont seem to be extending their feeders much if at all. i stopped dosing the b-ionic and the temp is back to normal so i hope they will bounce back.
have any of your tank params gone out of whack recently?

 

[sucram]

No, I havent had any parameter changes recently. I fed it a chunk of Formula I and it, very, very slowly, opened a few of its mouths and ate it. I'll keep doing this every couple of days and see what happens.
Another thought is that at about the time this happened, my xenia colony had reached an incredible size. I even had to harvest a bunch of them and lay them out on a shelf I had made in the tank, hoping to get rid of them. The question is whether that many colonies could be producing high levels of chemicals toxic to the brain. Anyone know anything about this?