acan/ candy cane help... ideas needed

I've posted this up on RC and 3reef, but not many people have any idea about what could be going on.
Ammonia - 0
Nitrite - 0
Nitrate - 0
sg - 1.025
alk - 9 dKh
Calcium - 440
pH - 8.3
Temp - 78*
Here's what the first acan looked like when I got it:

I popped it off the frag plug and super-glued it to some rock about 1/3 of the way up the tank.
Here are the acans as of a couple days ago:

This happened decently fast... it decided to deflate and then the tissue recession hit hard. 
The only thing I can really think of is possible alk spike when I added new base rock.  It clouded the tank a little.  It's also possible the LEDs are/were too intense for them.
Here it is as of today... I flipped the rock so the acan was right next to the sand bed.

So that's the worst acan.
Next up is the candy cane...
Here it is a couple weeks ago:

Sorry it's blurry, it wasn't the focus but you can see how inflated it is.
Coinciding with the acan recession...

And today:

I'm not sure what has settled on the glass, but I don't want to irritate it by moving the coral or cleaning by it.
Next up, another acan...
When I got it:

This deflated a day or so after the first acan:

This one had a small problem when I popped it off the frag plug, the skeleton cracked, but it was inflated for a couple days after that happened.
Today:

The last acan looks pretty good (considering the others)

Here it is today:

Now the funny thing about it is... not all of my corals are having issues...
Blasto Merletti looking healthy as ever:

(Yes, I see the small aiptasia there)
Zoas are ok:

RBTA is happy...

So, this morning I did a 30% water change, I've pulled out the Purigen (I had regenerated it and put it back in near the time the recession started so I thought it might be related), I dimmed the LEDs and reduced the photoperiod by 3 hours. 
I'm out of ideas as to what it could be other than light shock from the intensity of the LEDs, alk spike from the base rock or possibly bleach still in the Purigen (even though I soaked it in RODI+Prime).  Anyone want to throw some ideas my way?