Help me figure out what's wrong. (pic and video)

[Glasstapper]

My bleeding heart tetra is acting strangely. Here's what's different:

-He's not staying with his school.
-He's not eating.
-He's swimming around like he's drunk (wobbly and running into things)
-He's opening and closing his mouth constantly.
-He has a slightly raised black speck on his side. (I noticed it several days ago, but didn't think anything was wrong because he was behaving normally.)
-He's keeping his dorsal fin down.

tank stats:
ammonia 0.5
temp 78 F
pH 7.2
hardness 120
nitrite 0
nitrate 0 (my tap has 20, but it's not showing on the test)

I'm on day 9 of cycling, I feed twice a day, I do 10% water changes every other day/every day to keep ammonia reasonably low. As for chemicals, I've just been using pH decrease (very slowly) to suit the tetras, dechlorinator, and a little bit of bacteria supplement.

Pic:
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sorry about the quality. my camera isn't the best, but you can see the lowered fin and the black spot.

Here's a video:
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I can't seem to find any information about what's wrong with him. It seems it could be a number of things. He's the only one like this, by the way. The rest are normal.

[Glasstapper]

maybe this picture is better?

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[Glasstapper]

oh, crap. I just noticed another fish has a red thing hanging out of it's butt. The internet says it's camallanus, a worm.

Do you think I should medicate in a cycling tank, or remove the infected fish?

[William]

Medicate the tank. It will slow down cycling but is best to make sure that the disease is gone from the tank.

[Glasstapper]

nevermind. He died. I found him stuck to the filter this morning. :cry:

[William]

sorry to hear that.

[MagickFish]

I think somthing was wrong whit his swim bladder. Fish do that kind of thing when there som somthing swrom whit their swim bladder and they are usualy goners when they get that condition anyway.

[Glasstapper]

Yeah, he died soon after. I'm just glad it wasn't contagious to the others.

Oh, and that other one I thought had a worm? Haha! Nope, it was just poop. I didn't realize you would actually see them poop. Let me remind all of you that I have never owned fish before, so I felt quite silly at this discovery. Good thing I hadn't yet treated for worms! :D

All the guys are doing great. I'm amazed at their energy and personality. I wish I could tell what sex they were, though. I know the chances of them breeding is next to impossible (which is good because I'm not interested in breeding just yet), but I'd like to be able to tell. I think they're still too young. They are about 1 inch long.