Hello, one of my Tiger Barb's mouth is looking a little odd and maybe ill, he's been sitting in that same spot near those white rocks there for the past 2 days, I'm not quite sure so I thought I'd ask on here. I'll do my best to give specifics for everyone. My Aquarium is a 29 gallon marineland eclipse, my light is a CORALIFE 50/50 T8 15 Watt. My filter is the National Geographic IF30 internal filter system which puts the air in the water also, and my heater is the Tetra HT30 100W submersible heater which keeps the water at 80-82 degrees Fahrenheit. I currently have 8 fish in this tank, 5 Tiger Barbs(including this ill looking one), 2 Algae Eaters, and 1 Bala Shark. I added the other fish a week before the Bala Shark however. When I added the Shark, I also added that light and a new prop which is a battleship from the aquarium prop isle in PetSmart. The reason I'm mentioning this is because I didn't rinse it off or clean it before putting it in the tank which I should've done, it could've had something in it to cause this? Please let me know below if you what this might be? I apologize if the image is a bit blurry, it's the best I could get of him because they tend to scatter when I come up close to the tank.