frogspawn dying/dead......help

[Reef Tank 2.0]

I have had my frogspawn for a good 4-5 months.  It was getting bigger and bigger and looking really good. All was well.

this past week, i started dosing alkalinity to get it up from 7.7.  Within a few days, I had it up to 9.0+/-.  Right now, it resides at 8.9.

Nothing has changed in my system.  it has been consistent day in, and day out.  I can't imagine raising the alk to 9.0 would cause this to go in to recession.

I am attaching a picture of it, as it looks now.  It has recessed in to it's skeleton and only a few green tentacles are shown.  The picture isn't that great, but the white you see on the left is the skeleton.  and the green, remaining "bubbles" are on the right.

All my other corals in my tank are doing really well.  Nothing is showing signs of receding, or dying.

my current parameters are as follows:

calcium 400
magnesium 1400
alkalinity 8.9
nitrate 60-75ppm (yes it's high, always has been)
ph 8.1
ammonia 0
nitrite 0
temperature 79

any ideas why this coral went south?

[Topekoms]

you might have raised it too fast and that would cause that.

[Grymtooth]

I was thinking that as well, just too rapid of a change for him. As long as there's still some green, he should bounce back, but do keep and eye on it. I have come to losing mine due to an overpowered light bar before.

Sent from my SM-N910V using Tapatalk

[Topekoms]

I would say it is toast very rare for something that far gone to recover sadly

Sent from my XT1585 using Tapatalk