Earlier this year i switched from a 16gal to a 29gal and almost all of my corals died. I used everything from the previous tank. I tested and i noticed i had .5ppm of both ammonia and nitrite. It only lasted about four days but i still lost almost all of them. Mine werent even sps. The corals that i lost were some zoas, zenias, and a bubble tip anemone. My candycane coral the only one to make it. Seeing as how mine didnt last but four days maybe yours did the same, possibly even faster before you could even notice there was a problem. Just sharing my experience. Sorry for the losses