Capien wrote,
has some slight red puffyness around her gills...

Like Altum, I didn't see any redness in your photo, so ruled out Costia
right off the bat. Now that you are seeing redness, I would have to
agree with Altum as it may very well be Costia. With Costia, the
redness is blood spots under the scales. The red areas tend to start at
the base of the pectoral fins and gill areas. Costia is a parasite
infection and like Altum said, is treated with an anti-parasite
medication such as QuickCure or Rid-Ich...

I typically add about half a tablespoon of Jungle brand aquarium salt
at water changes. I didn't put a new dose in the hospital tank at the
rate Frank suggest as I didn't know if there would be conflicts between
the salt and the medication, is that a real concern or should I add the
salt as well? ....

A tonic level of salt (1 tablespoon per 5 gals.) along with the
medication treatments won't hurt a thing as for as the fish go. If it
is a Lymphocystis virus, salt is needed. With Lymphocystis, the patches
would be greasy looking (shiny) buff to white in color. Most of the
time these patches show up on the fins and tail first, and cause no
redness at all...

I'll up the water changes signifigantly as
suggested from now on. That should help the green
tank too I'd imagine....

No, green water is an algae bloom - your looking at the algae spores.
Water changes don't help, and many times even make the algae bloom even
worse because of the silicic acid, phospate and nitrAte in the tap
water. Algae blooms are caused by excess nutrients (DOCs) and to much
light or direct sunlight. The spores can be filtered out with eather a
diatom filter or a micron cartridge. An ultraviolet sterilizer will
kill the spores as would a product called Acurel. You may be able to
find Acurel at a garden supply as it is used in outdoor ponds
also................. Frank