SPS problems

[bullit67]

So I am having a problem keeping my SPS alive. I have done all my water test and everyting is OK not perfect but no real problems. I am realy scratching my head on this one. Any ideas would be good I know there are lots of variables that affect corals so \i will list some of the perticulars.

water quality
PH=8.3
Po4=0.01-0.05
No2=0.1-0.2
No3=5.0
NH=0
KH=6-7.5
MG=1000-1100
Ca=400
potasium=325

the system gets 9 hours of PC light 4x96 watt and 6 hours of MH light and PC 3x250 watt
skimming wet getting about 6 cups aday
running the full Zeo system
Using H2O salt