Im not trying to Hijack, But Most of my SPS are brownish as well. I checked out all my levels and I get:

Nitrates: 20ppm
Nitrites: 0ppm
Salinity 1.0245
Alkalinity: est 250ppm
PH about 8.4
Phosphate reading 0 but Unsure if its slightly a tiny bit

Temps stay at 79-81 never higher or lower and fluctuate from the 79 to 81 from 3pm - 9pm it hits the 81 or so around 9-9:15 then the chiller comes on and keeps it constant until the lights go off then it gets to 79 around 12. It never fluctuates more or less though.

I dont think theres much else in why. I use the B-ionic 2part but shame on me for not testing for Calc.... I need to buy a new test kit this weekend :S

Maybe you have the same Issue, I think my Calcium to Alkalinity is off... I wish I could get a little more training on this stuff. Maybe someone would like to come out to Canyon lake One of these weekends and give me a good briefing of SPS.... Or I could swing by and get some help with someone :/ I need to learn a bit more about it before I kill everything haha.