Galaxea issue

So I've had this Galaxea for two weeks. I started it high because I have weak leds. It never extended its tentacles in the high flow area. So I lowered it and put it in medium flow and after a week it looks like this. Almost like its melting. Tips are brown.







Ammonia and nitrite 0, nitrate 0, ph 8.2, 1.026 and 79