I do have SPS frags. I used to dose two part B-Ionic (Calcium and Alkalinity), but I've since switched salts and have found that I do not need to dose as long as I have weekly water changes with this salt (SeaChem AquaVitro Salinity). It's an expensive salt, but it's worth it.
Frags, lets see:
ORA Red Planet
ORA Hawkins Blue
ORA Frogskin
ORA Blue Enchinata
ORA Green Birdsnest
Orange tip birdsnest
Blue milliopora
quite a few no namers - various porites
ORA Aussie Delicate
ORA Miami Orchid
ORA Purple Plasma
ORA Tri color Valida
i have found that ORA SPS does the best and frags from other peoples corals. The pieces that are fully encrusted to their plugs do great. Also, when adding SPS, drip acclimate just like you would a fish and you'll get better results.