White Spot Turned Black

Hello, so a new Australian Rainbowfish of mine has a pinkish spot near its head, but I haven't really seen anything like it in other diseases. It also seems to be somewhat lethargic, as it only occasionally swims with its school and other times just sticks in one place for maybe half a minute before either joining back in or swimming to a new spot.

Should I be worried about the new spot, and if so, what should I do to treat it? None of the other fish in the tank seem to have it (yet). I've attached pictures of a recent water test results (PetSmart may not be super reliable), and the fish in question. The pictures are blurry, as the fish was constantly moving, but I hope the spot is still clear.

 

Might be an ammonia burn, from the pet store. It is caused from excess amounts of ammonia, and can cause sores on the body. It should heal up, if your water conditions are great! Maybe do a couple extra water changes for the next couple weeks!

 

Update: Spots have turned black and has started spreading; I've taken the fish out of the tank into a hospital tank. It seems like it's still ammonia burn, but I'm not entirely sure.

Added new pictures.

 

Also; there seems to be swelling on the right; is this ich? What should I do?

 

I got that with my goldfish. You can research, but from what research I have done, when ammonia burns turn black, they are healing.

Looks similar to what happend with my goldfish. Overnight his wounds turned black, and a week and a half after that they were healed.

Is he still acting normal? I might keep him in the main tank if I were you, I don’t think it is contagious, and the stress of moving aquariums can make issues worse.

 

That's okay, but I'm now more concerned with the white/pink bulge on the side of them. I really want to move it back to the main tank to reduce stress and not have to worry as much about the sanitation, but I also don't want to risk an outbreak. It might get better over time, but I'm not sure as of now.

It kinda looks like a cotton wool spot, but again, I'm not entirely sure. Is it safe to put it back in the main tank, or not?