I have one teenager (cory) that wasn't looking too good yesterday, laying on the side, not moving much. Today i thought it was dead but every now and then it hoons up to the surface, twists and turns, flips and flops back down to lay on it's side. So I took it out and put in in a floating container, added some fresh water, an airline and watched. Now its just laying upside down and breathing real fast. I know its not going to make it but could i have done anything different? (apart from taking it out yesterday)

Sounds like he is on his way out and not sure anything you could have done would have prevented him from passing further toward fish heaven