My tank is 135g long and is about 4-5 months old. Right now I have a yellow tang & 6 line wrasse that's been in the tank since it cycled & cleaner shrimp, black brittle starfish that's been in the tank for 3 weeks to a month. New Maroon clown fish & clown tang that I added today. deceased fish that were added at different times are blue spine unicorn tang, maroon clown, 2 mandarin, 4 anthias, 6 cardinals, & hippo tang. Seems like when I add a fish or two they do good for the first few days to a week then they start going down hill.I don't have a quarantine tank. Which I'm seriously considering setting up this week. I acclimate the fish for an hour to 2 hours. I buy my fish from maximum reef in yonkers. I noticed a little heavy breathing in some of the fish and I try to increase the oxygen. The marroon clown fish had white spots on it seen to be ich. They all seemed to be healthy when introduced to the tank.