Are these guys the culprit?

[90sShooter]

I recently noticed that a couple of my sps (blue tenuis, blue prostrata, red prostrata, and sometimes my bali tri color) have shown less PE. The first one I noticed was my blue prostrata which is usually very "hairy". I noticed that instead of the polyps coming out like 3mm they were more like 1mm and showing lots of skeleton (not sure if you call the base the skeleton cause it still has flesh...). I checked all my parameters and they seemed to be ok... My calcium was pretty high (around 540) and I thought this might be the reason. I stopped dosing for one day to allow the calcium to come down on its own and it did... I then did a 20% water change and it has been 2 days and PE is still not much better. Everything checks out... alk is stable... temp ranges 78-82... Now I am thinking my new addition of 3 "purple chromis" (as I was told they were called). Are they nipping at my coral?

Here is a pic... please help me ID fish (as I cannot confirm "purple chromis")

Are they possibly the cause of the reduced PE in my sps?

 

[Peter Eichler]

I doubt it. That does look like a juvenille C. scotti and they're typically planktivores that may consume some algae. I've never heard of them picking at corals, but stranger things have happened.

 

[90sShooter]

I kinda doubt it too as I have not caught them... a buddy told me they are known to eat acro eating flat worms... or did he say they ARE acro eating bastards... lol....