After having my tank setup for 4+ years all 4 of my fish died within a week. I sent out a Triton water sample and everything came back good. I thought maybe disease and left the tank fallow for 6 weeks. My zoa polyps quit coming out for the first time in several years during this time. After 6 weeks I added a clown fish and royal gramma and both were dead within 24 hours. I added a orange monti digi at the same time and it was Dead and bone white within 24 hours as well. My last thought as to why was stray voltage. I tested with a multimeter and had over 5+ volts in the tank. From what I’ve learned that isn’t enough to kill fish and coral, especially within 24 hours and could just be faulty reading from a cheap multimeter. A few others have suggested toxins in the water. I am thinking it is best to tear down and start over, especially since all of my inhabitants are now dead. I plan on draining all water and throwing out all live rock. I ran a bare bottom so no live sand. Soak all equipment (heater, mp10, return pump, skimmer) in vinegar and wipe out aquarium with vinegar as well. Am I missing anything? Anybody else have any advice on a tank restart? I think this time I’ll order “the package” from TBS once all is ready again.