Looks like I'm part of the "unlucky" club!

I finally got myself a zenia frag in the hopes of an invasion of propagation..

Unfortunately, it appears I may be part of the "just can't keep em" club..

I don't get it. I tried a few days partially shaded at the bottom, open at the bottom, and mid-tank. It seems that no matter where I put it, they just slowly disintegrated. Every day, more heads would be missing from the stalks, ending in what looks like half the mass of the original frag. Of course, the leather coral I split has doubled in size, and the small birdsnest frag is equally thriving.

Any suggestions for a hearty spreading species for my tank? I'm running a 90 gallon under a 150W MH (soon to be two)
Or maybe an idea on how to support the zenia? I know most consider them overpowering, but I'd readily support a tank full of something of that sort. I like the appeal of the movement!

Thanks in advance!

Here's a pic of the right side of my tank from earlier today, and a night shot of the frag wasting away..

Well, that does it..
2 days later, and they're gone..

Could still use suggestions for a similar frag that will propagate extensively..