What’s wrong with my Candy cane

[biggie4jets]

hey everyone, just wondering what do you think is wrong with my candy cane coral?? It was fine then all of a sudden...this. Pic was taken yesterday.

 

[Coralreefer1]

Are your water parameters good? What lighting scheme are you running? Try enticing your coral with plankton food. How much water flow hitting your Caulastrea

 

[biggie4jets]

Parameters are all fine, I do have low phosphates and almost always low nitrates. Water flow is low/medium, coral sits in the 1/4 of the tank near bottom. Lighting is a t-5 4 blub light fixture.