Do you know if your water has chloramine in it? If you have just chlorine, the detritus, surfaces, any plants and, uh, fish have probably taken up much of the chlorine. If you have chloramine, I would still dump a chloramine "neutralizer" such as Ultimate, Ammolock, the original Amquel, Prime or whatever, in there to break that bond between the chlorine and ammonia and to dissipate the chlorine and temporarily "bond" the ammonia (which is probably less than what you removed with the water change anyway.) Your sources of filtration and aeration should be doing a number on the chlorine too, especially if it is just chlorine in the water supply.

We have talked about adding a dose of Melafix to sooth messed up skin (and in a sense the gills are a sort of tissue not too far distant). This may be that exceptional situation where a little (non-table) salt, at least a teaspoon per gallon, would be useful. We have even talked about adding vitamin B to aid healing of tails and wounds.

I don't know if I would do it to your tank (maybe mine), but if healing doesn't continue apace, I might consider anchoring a vitamin B suppliment in the out flow of your powerhead (with a rubber band attaching it to an ornament?). Maybe an E would go in there too. If the fish seem to be rebounding, I probably wouldn't play around too much with vitamins.

They also have these aquarium vitamins in some of the shops. They are not cheap. If you are still looking to appease your guilt ;) you could spring for a container of those and dose as recommended. (If you were down the block from me, I'd drop a package off.)

You are probably over the worst of it. Your fish, if not stressed, should be on the mend.

You know this, but for the benefit of a lurker who might need the info, don't introduce any new fish to that aquarium for a time, perhaps a month.