120 gal FW tank. Mixed sand and stone substrate, Aquaterra background. 2 XP3s for filtration.
Take your time to set up right. This tank took me months to set up, since I wanted to get things just right.
5 angels, 1 rubber lipped pleco, 7 convicts, 10 various corys. Some feeder wild guppies that are fast swimmers (from my other tank of wild guppies, I don't use store bought feeders)
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.