20 gallon Glass Catfish Tank, Marineland penguin 100 (for up to 50 gallons) HOB filter. Regular lid with light, 1 sponge filter medium.
These cats need to be in a school and have a shaded hiding place. Feed just the amount of frozen bloodworms that can be consumed without too many being abandoned on the floor.
2 amazon swords, many bundles of elodea waterweed free floating for cover, 1 anubias small, 6 marimo moss balls.
Nothing beats getting all "cheesed up" and fuckin with aquariums man.
When you see signs of stress in your fish, you can then take steps to identify the source of that stress and then to resolve it before it becomes a major issue.
If you're looking for a unique way to stock your new tank, give freshwater shrimp a try.
If your fish is suffering, you may want to consider euthanasia as an option to humanely end his pain.