I always expect any wild fish to arrive with some type of parasites, and have not been proven wrong.
One of the Andinoacara seems to have a touch of Lymphocystis (or something similar), and a Roeboides tetra and another Andinoacara a touch of ich.
The Lymph is viral, so no effective treatment.
To treat the tank for ich, (there are no LFSs on the island, or even stores that sell enough salt in the kind of bulk needed for 180+ gallons). Everything expect ocean fish or fruit like papayas, or star fruit requires a ferry to the mainland.
To treat for ick, I calculate the tank needs almost 6 lbs of salt, but..
since the sea is less than 50 yards away, between 2 and 3 gallons of 35 ppt sea water to get a target salinity of 3.5ppt.
Im hoping the salinity won't destroy the plants, and the shrimp, but sometimes sacrificing 1 to save many (in the parlance of our time)......