My tank is 100 litre, so not huge. I have had the mandarin fish for 4 days... He seemed really settled, eating, swimming etc. I do hear clicking, but that is usually my pistol shrimp or my mithrax crab, both of these click. Both of these have been fine with everything in my tank so far. I have a bubbletip anemone with clown fish, pistol shrimp with goby, bangaii cardinal fish, 3 hermit crabs, 2 cleaner shrimps.
Janet