I just saw your other thread... Sakura8 responded and she has never steered me wrong! But to be honest, the rapid desintegration/normal behavior makes me think bacterial as well. Either way, it sounds like you have both parasitic and anti-bacterial meds?
You should not have to worry about oxygenating the water. Honestly, I don't see how this would help as they get their oxygen from the surface, not the water. As someone has already said, stay away from meds with -fix at the end as they may suffocate them by destroying the organ they use to breathe.
Otherwise the only advice I have to add is that it will be OK to remove the air hose if you feel that the water movement is stressing him. We want to keep down his stress levels so that he can recover!
I wish you both luck.