Losing skin from top down

[dcsaquarium]

I got what the lfs told me was a Pavona malvincis along with other SPS corals. However this coral I think I put it too close to the direct flow of the power head and I started noticing tissue loss on the very top of the coral so I moved it away from power head but it is continuing to lose tissue even though I moved it. It is going from the top down and has slowly been working it's way down over about two weeks. Any suggestions?

 

[DSP]

What's your alkalinity reading?sounds like could be alkalinity burn to me, Btw this is David from in2deep

 

[DSP]

I would frag the bad parts off if you can and try to save the rest of the coral because it could be tissue necrosis as well.

 

[dcsaquarium]

According to my alkalinity test it's at 9 but I guess the test could be wrong. I need to get some different tests. I have been slowly rotating out of API.