I currently have a 10 gallon heavily planted tank that has been running for about 5 months. There are 6 neon tetras that currently reside here. Overall, they have done fairly well, I had a small case of ick early on but that has since cleared up. I started noticing though that one of the 6 hasn’t been acting normal. It’s fins are ripped up (most likely from the others nipping him), some of it’s scales are hanging off like they had been nipped off too, it’s coloration is very pale, it’s eyes seem to bulge out more than the others, it is never with the rest of the group, and it is significantly smaller than the rest (it’s eating just fine but seems to be developmentally smaller even though it came with the first batch of three that I got after the tank had been cycled). The other 5 are completely healthy, and my water levels are great. What could this be?