This page gives some general care information
- When feeding your goldfish, only feed them what they can eat in a few minutes, once per day. And I find that my fish are healthier if I skip a day per week.
- Don't keep your fish eating the exact same food every day, and try to give them something besides petfood (peas, lettuce, etc..) at least once per week.
- Keep the water clean. Use testing kits to make sure that the water quality is correct.
- Goldfish need a place to hide and interesting places to forage for food. Live plants and decorations can provide this.
- Make sure that if you have fancy-tailed goldfish that you don't have too many sharp decorations like castle spires or things like that which can rip their long fins.