Thank you for your willingness to help me with my fish issues. Unfortunately, I am not as knowledgable about fish/aquariums as most people on this site. I'm doing a lot of research to try and catch up!... but as of now I'm in the initial phases. My neighbor comes over to test my water, since I don't have my own stuff as of yet. He'll be over on Saturday.
Update: the barb was looking better after he was in the breeder for a few days. He wasn't resting on the bottom anymore, so i let him out. He was looking alright, aside from the recessed stomach. He died yesterday. =( Someone else saw him and took him out of the tank for me, so I didn't see the fish, but it was described to me as "it looks like whatever was inside his stomach ate its way out... unless the other fish picked at him that badly. His stomach was missing and the whole body was pale."
The rest of the barbs in the tank are completely fine (I must have just startled them early in the morning when I turned the light on. Apparently I was told that later that day they all looked healthy (except for the one guy, of course)).
Anyway, I'd still like to get feedback (once I get more info for everyone) because another one of the green moss barbs looks like he has a slightly recessed stomach, and he's not swimming with the rest of the group. He seems to be hanging out in the plant quite a bit.
Oh, and unfortunately I don't have a digital camera.