I have a 20 gallon planted tank with one very calm red tail shark 7 ghost shrimp and 3 neons, yes im aware I need 3 more for a school. I bought one of the neons last night, my water conditions are perfect and I use RO water in my aquarium. The new tetra looks healthy great color and seems to be eating, but im concerned because it looks like its constantly chewing, is it sick possibly trying to breath, it also seems to kind twich its fins,maybe just to stay in one place, looks heathy otherwise just concerned about the one issue, I put stress coat in the tank as well and the temp is at 77 degrees F. Any info is much appreciated.