I've had a 29 gallon w/10 gallon sump for a couple of years. I am now in the process of transferring stock to a larger tank-75 gallon w/55 gallon sump. All has gone very well with smaller tank. I transferred approx. 15 lbs of my existing live rock and seeded the new sand with 4 cups of my old sand. I started approx. 3 to 4 weeks ago and have a GSP and Pulsing xenia that have been in the new tank for 2 weeks and are doing well, but I have place 3 green chromis in the tank and lost them all. I could never find them, but I'm showing no ammonia, nitrates or phosphates. Was it faulty fish? I would like to start transferring fish from smaller to larger tank.