very happy with sc reef salt, i switched over from kent a few months back. my calcium was alright, but as mentioned alkalinity was always low and had to be buffered constantly with kent. i believe my alk back then hovered around 6-8 dKH and calcium around 380. last time i checked with reef salt (with regular calcium+alk buffer of course) i'm stuck at 460 calcium and 8-9 alk. i've heard from alot of ppl that kent salt is starting to go down hill so i decided to give reef salt a try and am pretty happy so far, hope that helps
