I have had my saltwater tank for about 4 months now. The first few fish I put in, domino damsels, are fine. I added them after a month of cycling. During the second month I added a Yellow Tang, Foxface, a Coral Beauty, a small Clown Trigger, a Sailfin, and a few clown fish. The Foxface died after a few weeks but he looked stressed from the time they bagged him up. Over the past two months I added a new Foxface, I bought a Flame Angel that died the very day after I bought it, I bought a small Humu (Picasso) Trigger over the weekend, and a flame something... My clowns look fine, my Clown Trigger died two days ago, my Yellow Tang and Coral Beauty both died today and my Sailfin is looking rough. My amonia, PH, nitrites, and salinity are fine. My nitrates are high so I did a partial water change and added some Prime and Microbe-Lift Xtreme. What could be causing this to all happen at once and what can I do to save my remaining fish?!?!