I recently (2 months ago) moved my 26 gal. reef tank to my new apartment. I saved 20 gallons of the water, individually contained my inverts and fish,...basically did everything as carefully as possible. A day after I set it up, all my fish died! The clarkii, royal gramma, and flame hawk were as old as the tank - bout 6 years old. My various polyps, zooanthids, mushrooms, snails, are all thriving. Whenever I tried to add a new fish, it would die within 24 hours. The ammonia never spiked, and the nitates/nitites stayed very low, so I don't know what the problem was. Any insight?