I just made an account for this forum because I wanted some advice.. I'm currently keeping 5 tiger barbs in a Marineland Eclipse 12 gallon aquarium (I am aware that I am slightly overstocking, but I am planning on getting a bigger aquarium by early next year) and I am concerned with the behavior of one of my tiger barbs. The tiger barb in question is actually the smallest of the fish in my tank, and is different from the others for two reasons- a. His/her scales are a darker hue than the others, and he/she stands out even when they're right next to eachother. b. He/she seems to be a weaker swimmer than the others, often facing upwards or sideways when trying to move forward. Is this a problem? Is my fish ill? If so, what should I do?