My Cory is swimming really fast everywhere and seems to be floating upwards a little bit

[Franksteemac]

Hi, I have recently noticed that my Peppered Cory has quite a few small golden patches on it, it is swimming around quite a lot and is starting to float a small bit. Is this normal or is something wrong with it? Everything in the water is as it should be

 

[Naughts]

No that's not normal. The gold patches you describe could indicate a microscopic external parasite called Velvet disease. I can't see anything in the photo. I have no experience of treating this so will let others advise you.