What kind of temp swings are you getting. The key to keeping sps is stability. Stable Alk, CA and temp. If your temp is swinging from lets say 79 at night to above 83 during the day then your going to bleach sps. Not to say that you cant keep sps at higher temps because I have seen it done, just a 3 degree swing can cause them to bleach. I dont know alot of people who keep their alk at 12, most are in the 8-10 range. If you were to put sps in your tank at an alk that high you probably will kill them. Just some things to keep in mind.