Really starting to hate SPS

[Murminator]

Ok yesterday I came home to 2 dead large acro frags and 2 1/2 dead digi colonies (1/2 was still alive) and a small birdnest that doesn't look so hot. I did some tests and did a 10% water change
PH 8.3
Cal 440
Alk 9
Mag 1380ish
all done with new salifer kits
And everything else (LPS and softies) is looking awesome There is a slow growing milli that looks fine and a small cap frag that looks fine also.I can never seem to keep SPS I maintain life for a few months with little or no growth before it rtns
I added a calcium reactor a month with the hope everything will change but it seems noth has changed
What am I doing wrong???

90G 9.5 return pump, hydor #3 100#+ of rock