Tiger barb injury - QT questions

So, last night I found that my second largest tiger barb has been injured. His left gill is blood red, as is his right pectoral fin (or at least, his body surrounding where it's attached). I imagine there was a tiger barb battle, as tiger barbs are won't to do, and I've seen him scrap mouth to mouth with one of the other boys before. It's possible the rainbow shark got scrappy, too, when the tigers went after the food on the tank floor. EDIT: Upon further inspection, his upper lip is every bit as red. I'm thinking tiger barb fight.

Today I plopped him into a 10 gallon for quarantine, along with an uncycled sponge filter that's being fed off a severely overpowered air pump. I'd like to use a smaller pump, but then I'd have air line crossing my kitchen and causing trip hazards.

Is it fine if I just keep him with an air stone that makes finer bubbles instead of the turmoil this sponge filter is causing? I understand he would have no filtration, but I imagine less stress is key here, and I can give him daily water changes and treat with prime in the meantime.

Is there anything I should medicate him with as a preventative for infection? I only have Prime, Stability, Kordon's Rid-Ich plus and some API Bettafix on hand but I can make a quick fish store stop on my bike tonight if need be. I don't have aquarium salt.

Will the rest of the school just get mean again with him once I reintroduce him? They were pecking at him today, I assume because he's injured and off hanging out on his own.

Uploading a video to YouTube now...

You can see how red he is on either side, though he's frantically trying to rejoin the school so he won't sit still much...

 

How many tiger barbs do you have, and what size tank?

Sponge filter shouldn't be throwing him around. Using an airstone with finer bubbles (possibly less air escaping) from the pump may cause the pump to overheat. I would use a splitter in the tubing and leave one side to air out, so less air is going to the sponge filter.

I wouldn't medicate at this point. Daily water changes should help. Make sure ammonia doesn't get above 0.25 ppm.

 

9 tigers in a 75g. The pump has a second unhindered line powering the sponge filter in the 75g.
I'll set that up anyway and see how it helps.

Edit: no good. The sponge filter has zero air supplied to it using the T.

 

You can get a piece to control the air flow to the tubes too

 

Unfortunately, I don't have one on hand as all three of mine are in use.
Can I ask how it's different to constrict the air flow with a valve as opposed to an air stone?

Edit: I've kinked the hose lightly, held in place by a rubber band. It's doing the trick for now, at least. The water is no longer violently bubbling.

 

You would use the valve with the splitter so it's not completely going out the open end (you put the valve on the open tubing part, and reduce the amount let out so some goes to the sponge filter). But since you don't have one, it won't work.

 

Update: the blood red spots have returned to normal colour (there still appears to be a gouge in the spots, albeit healed gouges) so I returned him to the 75 today. He had lost all his shine in the QT, and constantly stayed pressed up against the 75 with the school in the 75 staying as close to him as they could (tanks were side by side so he wouldn't feel so alone). The second he returned, he rejoined the school like he never left it and the school was more interested in the bag he was transferred in to bother with him. Will keep an eye on him and continue to watch for secondary infection slash bullying, but at this point I believe it all went well~

 

If your tiger barb was mouth to mouth then it was most likely fighting, but to be sure I would check your plants... A while ago two of my tiger barbs somehow got cut on them but mine never fought they just chased each other into the plants... I'm glad everything worked out though! TBs sure are tough!