Problem with SPS

Hi

I have the following SPS that are not healthy (see pictures).
I have no idea why.

Some data:
Aquarium: 567l
Sump: 140l
KH: 7,06 DKH
Ca: 485ppm
Mg: 1470 ppm
Salinity: 1,027
Temp: 25,2c (average)
PH: 8,06 (average)
PO4: 0,1 mg/l
Nitrit: 0,0 mg/l
Light: LED Maxspec Razor 320W (75%)
Streamer: Maxspec gyre
I did water change each 2 weeks (70l) during 1,5 months and I use tap water.
The aquarium is about 2 years old.

Any idea?

/Oualid

Attached Thumbnails