Advice? Lithophyllon deteriorating

My litho isn't doing so well, it's got some pretty bad tissue recession going on. Almost everything else in the tank seems to be doing very well: psammocora, stylo, trumpet, shrooms, Monti, zoa, war, nem, acro. The only other thing is my blasto seems kind of pale on the underside of the pink outer rim, kinda hard to see in the picture. I've recently been turning my light intensity up, so this evening I moved the litho into the shade of a plating Monti thinking these two corals aren't liking the higher light levels. The blasto is epoxied to the rock, so I'll just have to take a break in turning the lights up higher. Tank gets phyto daily, spot feeding reef chili 2-3x per week. Maybe someone has another opinion.

BioCube14
SG 1.025
Alk 9-10
Calc 425 ppm
PO4 ?? ppm (lowest end of the scale, can't remember the exact value)
Nitrite 40 ppm (working on bringing this down, got some algae in the back chamber recently, reducing feedings)