Your pH is low. You need to try and bring it up to 8.3 to 8.4. I am not sure if it caused the death but it could be a very good possibility that a sudden change in water chemistry could cause the fish to stress to the point of death.
__________________ Clarence  55g sumpless mixed reef(soon to be 120g)
DSB(2 to 6 inches)aprox. 80 lbs,LR aprox. 60 t0 80 lbs.,Coralife 220 Protein Skimmer,CPR HOB Refugium with Fiji Mud Member of TRS Member of SDMAS
RIP Sarracino Ciro 12/16/04 - 4/3/08 | 
