Id, lighting help

[bmasculine]

So I bought this in Dec. and it has shown very little growth. I'm wondering if too much light or to little? It tword the top of my tank about 8" below water line. It's a bluish purple with green coralites, although very hard to tell from crappy iPhone pick. Just wondering if someone knows what this is and best placement. It's about 2.5 inches tall for reference.

 

[reefbroao]

Some kind of tort. Not really able to give a strong ID

 

[bmasculine]

Here is another pic under different lighting.