PetsA goldfish is often a first pet, and often kept wrongly. It is not a fish for a bowl. Goldfish grow large, produce a lot of waste and can live for many years in a big, filtered tank. Set up properly, a goldfish tank is calm to watch and simple to run.
This is a care guide, not veterinary advice. It covers housing, food, routine and safety. It does not diagnose or treat illness. If your pet seems unwell, is hurt or behaves differently, take it to a qualified veterinarian without delay.
At a glance
- Lives
- Often 10 years or more with good care
- Time each day
- 5 to 10 minutes, plus a weekly water change
- Space
- A large tank on a strong stand. A common guide is 75 litres or more for one fancy goldfish, and more for each extra fish
- Cost
- Medium at the start (tank and filter), low afterwards
- Good with children
- Yes. An adult should manage the water changes
Is a goldfish right for you?
A good choice if
- You have a level, strong surface for a heavy tank
- You can change part of the water every week
- You want a calm pet to watch
- You are willing to set up the tank some weeks before buying fish
Think again if
- You were planning on a bowl
- You want to stock many fish in a small tank
- Nobody will do the weekly water change
- The only place for the tank is in direct sun
What you need before the first day
- A large glass tank with a lid
- A filter rated for more than the tank's volume
- Water conditioner to remove chlorine
- A water test kit for ammonia, nitrite and nitrate
- Smooth gravel or sand, and smooth ornaments
- Goldfish food
- A net, a bucket and a siphon used only for the tank
- A thermometer
The right home
Bigger is easier: a large volume of water stays clean and steady for longer. Place the tank away from windows, or it will turn green and overheat. Before any fish go in, run the filter for a few weeks and let helpful bacteria grow in it. This is called cycling the tank, and a test kit shows when it is ready. Add fish a few at a time. Goldfish are cool-water fish and normally need no heater indoors.
Food and water
Feed goldfish food once or twice a day, only as much as the fish finish in about two minutes. Overfeeding is the most common mistake: uneaten food rots and fouls the water. A day without food now and then does no harm.
Never feed
- Bread, biscuits and other human food
- More food than is eaten in two minutes
- Untreated tap water straight into the tank
- Soap or detergent on anything that touches the tank
- Sharp ornaments that tear fins
Care routine
Every day
Every week
Every month
Handling and behaviour
Fish are not handled. Enjoy them by watching, and you will soon know each one's normal behaviour. When you must move a fish, use a soft net and a container of tank water. Never tap on the glass. Do not release unwanted fish into ponds or rivers, where they harm native wildlife.
When to see a vet
Do not wait and watch if you notice any of these. Go to a qualified vet:
- Gasping at the surface
- Clamped fins, lying on the bottom or floating oddly
- White spots, patches or ragged fins
- Not eating for several days
- Several fish unwell at once: test the water first
Find a vet before you need one, and keep the phone number where everyone at home can see it. Follow the vaccination and parasite-control schedule your vet gives you.
In India: climate and rules
In summer a tank near a window or in a closed room can get too warm. Keep it shaded, leave the lid slightly raised for air, and point a small fan across the surface if needed. During long power cuts, do not feed, and stir the surface gently now and then. Tap water in many cities contains chlorine, so always use a conditioner.
More guides
Dog, Cat, Rabbit, Guinea pig, Hamster, Budgerigar, Cockatiel, Betta fish, Tropical fish tank. Also: the first week with a new pet, foods pets must never eat, summer care.
Written in November 2026. Life spans and sizes are the ranges commonly given for well-kept pets. Individual animals differ.