You haven't looked very hard, it's all here in this thread. All you have to do is take a little time and read some of the links I posted.
What's your definition of crash?
It's all there in those links, they CYCLE NUTRIENTS, it's the release cycle (eutrophication) which creates an environment which promotes problem algae growth, and conditions which are, to some types of corals, lethal. Other corals could care less that nutrients are cycled, and all you have to contend with is problem algae.
I don't have to prove anything to you. These people have done all the work:
http://www.fnzas.org.nz/fishroom/2-vt10 ... =15#109090
Funny how people don't ask Dr Ron for proof of what he says. People just believe him, because they assume he knows what he's talking about. But there are lot of scientist which disagree with him, haven't seen one yet who does, as well as anecdotal evidence.
Doesn't yours perform de-nitrification? How do you look after them? What do you have to do to them? How do you stop them cycling nutrients?
Layton