Most leathers die in my tank except xenia

[oldpaddy]

What's up with that? I get that my sps, lps and zoanthid dominant tank might be too clean for leathers, but why does my xenia flourish?

220gal + 30g in sump, 2x 300w black box LED, weekly 30gal wc with reef crystals, auto doser.
0 no3
0 p03/4
400ppm Ca
8kh Alk
1.025sg

 

[Sk8r]

allelopathy? Chemical warfare?

 

[oldpaddy]

allelopathy? Chemical warfare?

I guess that's possible. I wonder which coral might being doing it. I have so many that I lose track.