110 liter planted freshwater goldfish tank, eheim classic 2215 external filter, home-made device to add CO2 to the water.
Trying to keep goldfish in a planted tank can, and will, be very, very frustrating. It takes a lot of time, and patience to make anything green grow in a goldfish tank. But, it's worth it :)
Anibias nana, Valisnera americana, Egeria densa, Hygrophila difformis and Hygrophila polysperma and some traces of Vesicularia dubyana.
Chuck Norris can kill to stones with one bird.
Something about me... well, I'm a chemistry student and I live in the Netherlands, and my hobby is, obviously, keeping goldfish :)
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.