Boxfish: I'll say that I doubt it's lack of nutrients.. I'm not dismissing it, but I dont think the corals would react in this manner if a lack of nutrients (nitrogen) was the reason.
Two main reasons are:
The corraline algae growth on the new bare bottom has been ridiculous. It's been in for less than 2 months, and it went from perfectly white, to this, in that time:
(Sorry for the crappy photo.. MHs arent on yet). If the tank were that free of nitrogen, could corraline do that while SPS zoo flew off?
Other reason is the current darkness in the tissue of the corals. Here is a purple humilis 15 months ago (rarely fed fish, only had like 5 or 6):
...and here it was not too long ago (I dont have a good picture of it, but it's directly below the Purple Tang in the middle of the picture):
http://www.d3f.org/misc/fish/90g/a11-full-tank.jpg
You can see how much darker the tissue is now than before. So, I have had a bit of experience with lack of nutrients.. it tends to turn the corals pastel.
Now, maybe I've experienced some kind of ultra sterelity? Is it possible my tank went from having adequate nitrogen levels to being so low, the tissue just disspates from the skeleton? I dont know.. I havent heard of that happening before, but maybe?
I will say Ive been trying to double my fish load for almost 2 months now, but I have not had luck getting the specific fish I want, so it's taking longer than i expected, but I do want MORE poop in this tank
