RTN or hopefully something else HELP

[reefermadness]

If you've only had it for 2 weeks....it may have been destined to RTN.

Also I've never had a acro RTN over redbugs.

[Aquattro]

Originally Posted by reefermadness

Also I've never had a acro RTN over redbugs.

Not RTN, but PQTN for sure. I've lost whole colonies, once they started, they were gone in days.
But probably not what happened here. Just a set of parameters that were likely too different to it's source tank. Too much light typically would cause bleaching, too little and it goes brown. PO4 is a bit high, so that could affect it.
Differing flow patterns, often bigger pieces are more affected. The fragging process probably wasn't the cause, I got a 1/3 of a tabling piece 2 months ago that we just cut into three. All three are doing fine in three different tanks.
Unfortunately in the world of SPS, sometimes this happens. If you keep those pieces that you cut off, you got lucky.

[RedCoralEdmonton]

also you say LED.... but what LEDs there are alot of different brands and styles to group your lighting into one category.... ive seen LEDs that suck and ive seen LEDs that rock... all being the same wattage....

Steve