My 30 gallon is covered in purple. I keep my calcium at 420 , mag 1400, and dkh 9. It looks sweet, wifey loves it, but it is actually killing any zoa growing on liverock. I've been watching it smother these zoas for the past month. This rock used to be covered with zoas. pic 1 is a close up of the zoas and corraline creeping up the sides. pic 2 is another close up. Pic 3 is a quarter pic of my tank. Anybody else ever see this in their tank?