Goldfish Care - Carassius auratus

Updated May 13, 2020
Author: Mike - FishLore Admin
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The Goldfish is a favorite fish for many. How many of us didn't keep them at one time or another?

They are usually very hardy fish and they can live in temperatures ranging from 40°F - 90°F (4°C - 32°C). It is important to note that this fish has an extremely long lifespan if cared for properly, so getting one can become a long term commitment!

Many varieties of this fish are available with many different markings, fancy goldfish varieties and colors including gold, orange, white and black. See the pictures throughout this page for the different types.

They can sometimes come down with swim bladder disease and occasionally freshwater ich. It's very important to provide your fish with frequent water changes and quality, nutritious fish food to prevent this from happening. Do not overfeed them though because goldfish are heavy waste producers with a large bioload. A larger sized canister filter will work great for them. Remember to change out or rinse out the filter media with tank water on a regular basis (once a week at least) to keep nitrates in check.

Carassius auratus

Red and White Pearlscale Goldfish
Red and White Pearlscale

Sinking foods or presoaked foods are recommended and only give them as much food as they can eat within one minute. Do not overfeed them! They are like little pigs and will keep eating if you keep putting food in the tank.

Many hobbyists only keep them with conspecifics (e.g. other goldfish). This is a long-finned, slow moving fish. Most barbs and tetra species are not going to do well with them. Not to mention the waste production from them will make it a challenge to keep the water on the cleaner side that many other species require.

Another problem with stocking them with tropical fish is the temperature requirement differences. Tropicals need and require warmer water temperatures. Goldfish on the other hand do much better in cooler water temperatures. That is not to say you should keep them in a tank without a heater. They will do much better if you use a heater so you can keep the tank temperature at a steady 72° F (22°C). Large temperature swings on a regular basis may be detrimental to most, if not all, fish species.

For the aquarium lighting, it is a good idea to keep the tank light on for at least 6 to 8 hours per day. If you start to have algae problems try cutting back on the amount of time the lights are on and step up your water changes and filter maintenance schedule. They need to sleep/rest at night and need a period of time with lights out.

Goldfish and aquarium plants usually don't do all that well together, which is unfortunate. Plants could help reduce nitrates and in general provide better water conditions for your fish. But, they will eat and/or uproot your plants. Java fern may be an option though and some members on the forum have reported success keeping them with java ferns.

To increase your chance of success with keeping them, try not to keep them in a tiny bowl. A tiny bowl will become polluted quickly and you'll have to perform maintenance all of the time. The fish will become stunted in growth and it is just really an inhumane thing to do. Instead get your fish at least a 20 gallon tank with a good power filter or canister filter. Also, if you want to keep multiples, try for a minimum of 10 gallons per fish after the initial 20 gallons for better long term success with this fish.

Goldfish Care Summary


Redcap Oranda
Redcap Oranda

More Goldfish Types

Blue Oranda
Blue Oranda

Chocolate Oranda
Chocolate Oranda

Black Moor
Black Moor

Black Oranda
Black Oranda

Calico Ranchu
Calico Ranchu


Goldfish Care Details

Scientific Name : Carassius auratus

Common Names and Types : Calico Veiltail, Comet, Black Moor, Bubble eye, Lionhead, Ranchu, Oranda, Pearl Scale, Ryukin, Panda, Fantail, Shubunkin (calico), Tosakin, Orange Fantail, Black Fantail, Pompon, Celestial, Telescope, etc. There are many different varieties of this fish out there.

Care Level : Common varieties are easy and good for the freshwater aquarium fish beginner who is willing to perform the frequent water changes required in smaller setups. Some of the fancy varieties can be slightly more difficult to care for and need more stable water conditions and high quality foods. See the summary above.

Size : Usually 3 to 5 inches (8 - 13 cm), but can get bigger

pH : 6 - 7.5

Temperature : 40°F - 80°F (5°C - 27°C)

Water Hardness : 5° to 20° dH,

Lifespan : 10 - 30 years, and often longer. This paper reports 43 years as the oldest recorded common goldfish.

Origin / Habitat : China originally, then Japan, Asia and the rest of the world. They seem to prefer more subdued lighting and studies have shown that they prefer dark places over lighter places.

Temperament / Behavior : Very peaceful

Breeding Goldfish / Mating / Reproduction : Not very common in home aquariums but you can try. Make sure you are ready to deal with the babies before you start your breeding program. Give them a water temperature between 75°F and 80°F. Get them ready by feeding fish food high in protein and make sure that they have good water quality. When they are ready, they will lay their eggs on vegatation on the bottom of the tank. You will have to remove the adult fish to prevent them from eating the eggs which usually hatch within 7 days. Prepare your fry foods such as infusoria and brine shrimp and have it ready in time to feed the babies.

Minimum Tank Size : preferably a 20 gallon or larger and 10 gallons for each additional fish if kept in groups.

Tank Mates : Usually do better when kept with other goldfish. Other potential tank mates include white cloud mountian minnows and similar cold water species. Watch closely if you introduce different species to your tank though and be prepared to remove them if it's not working out.

Disease / Illness : Freshwater Fish Disease - Diagnose, Symptoms and Treatment - Unfortunately, they can be quite susceptible to swimbladder problems due to the various types or varieties that have been produced over the years. Ich or white spot disease and fungus problems are also frequently encountered.

Fish Food / Diet : Will gladly accept most fish foods, including flakes, live and freeze dried varieties. There are foods made specifically for them like this: Repashy Food. They are omnivorous, which means that they will eat foods of plant or animal origin. Their diet can affect their color.

Tank Region : All over the tank

Gender : Males may have small white spots called tubercles around their gill areas when ready to spawn. Females may be noticeably larger when swelling with eggs and the males may start to chase the females around the tank.

Forum Avatar :
Carassius auratus

Recommended Reading :
The Goldfish Doctor, By Elaine Rushmore
Goldfish Owners Manual
Guide to Fancy Goldfish

Photo Credit : Photos copyright

References :

More Info:
Goldfish Care Sheet
Member's Photos
Goldfish Forum

Goldfish Comments and Tips

From: Danielle via email - care
Can I get information on how to take care of them?
Response: See above. They will do better in a 20 gallon tank with a good filter but you can keep them in a bowl. They just won't live as long in a bowl. No matter what you put them in, here are some suggestions:
  • Change about 25% of the water each week. Be sure to use a water treatment such as Tetra AquaSafe when adding new tap water. Also be sure to use fresh water that is as close as possible in temperature to the tank water.
  • Feed your fish a dime sized amount of food 2 times a day.
  • Use an aquarium vacuum to clean the rocks about once a month.
  • Enjoy your fish!

From: Marcella - Lifespan
What is the lifespan of this fish? I've had a small gold fish for 9 years.
Response: We've heard some crazy things regarding their lifespan. If cared for properly and given frequent Water changes, they can live as long as 15 years or more. It sounds like you are doing everything right if you have one that is 9 years old. Good job!

From: AJ - Food
What is the best type of food for them?
Response: For the beginner, we recommend a food made specifically for them. You could try to supplement their diet with some live foods such as Brine Shrimp from time to time. Give the brine shrimp as a treat every once in a while. Your fish will get most of the vitamins and minerals needed from the flake food and the brine shrimp will give your fish some extra protein in their diet.

If live foods are not an option then maybe you could get a freeze dried version. Freeze dried foods are not as messy as the live foods. Also, remember that 2 or 3 small feedings per day are better than one large feeding for your fish.

From: Catrina - Overstocked Tank
I have a 30 gallon tank with 1 betta, 1 gold fish, 1 fantail, 1 black moor, 1 sucker fish, and I was wondering what other fish can I put in there that will do well with those?
Response: Is your betta doing ok with them? Sometimes bettas become aggressive towards fish with large fins. As far as stocking goes, you should reconsider adding any more tropical fish to the 30 gallon tank. Your sucker fish (common pleco?) will get to be very large, usually 12-18 inches.

If you have a bristlenose pleco, they get to be about 5 inches and you may be ok adding more fish. If you do have a smaller pleco, White cloud mountain minnows or Corydoras could go well with your current tropical fish.

From: Carrie W. - laying on bottom
My gold fish stays on the bottom of the tank, is this a normal thing?
Response: I don't think that staying on the bottom would be a common thing for them. Without more information it is hard to diagnose what the problem is. However, your fish may have something called swim bladder disease which is fairly common for them. They can get this from a viral infection or from their diet. Some feel that flake foods contribute to this disease. Here are some things you could try:
  • No more food for your fish for the next 4 days. Don't worry, fish can go up to 7 or 10 days without food. If your fish recovers in that time period, then you may resume feeding.
  • Some believe that frozen peas will help in healing swim bladder disease. Chop the peas up into small enough pieces for your fish to consume. I've never tried the peas myself, but you never know.
  • Check your water parameters (nitrite, nitrates and ammonia) and perform more frequent water changes. Try for 25% water changes every week. This will help remove nitrates and the new water will bring with it some beneficial minerals for your fish.

From: Gold fish Frenzy - Keeping them with plants?
I have plastic plants in with mine, however many people have told me real plants are better for them as they oxigenate the water. Do you think I should get some real plants? Thanks.
Response: Live plants are better than plastic plants for many reasons. Check out the Aquarium Plants page for more information. However, they usually don't do well with live plants because of a variety of factors.
  • They really seem to enjoy uprooting plants and eating them.
  • Many don't have adequate lighting levels on their aquarium for live plants.
  • Many don't have a heater in their aquarium and some live plants require a higher temperature to thrive.
If you still want to give it a go, there are some plants that may survive with your fish. Start out by trying a plant such as the Java Fern or Anubias. These plants are some of the hardier plants available and should grow well in a wide range of water conditions. Many have reported success keeping Java Ferns with fish that love to eat plants. You may also want to try Hornwort (Ceratophyllum demersum) and/or Willow Moss (Fontinalis antipyretica). Thanks for the question.

From: Pam - Re-decorating Tank
I really enjoyed reading your comments and learned alot from your questions. I am new at this fish game and I have alot of questions. I want to rearrange my decor in my tank, can I do that at any time and what is the correct way to do this so not to harm my fish? Thanks
Response: You can rearrange your tank but you need to be careful. Remove the filter and keep it in a bowl of tank water while your doing the rearranging. The filter floss or filter media (bio-balls, ceramic rings, etc) will be where the majority of the beneficial bacteria are located that help in the nitrogen cycle. Remove your fish to a separate bowl that is filled with water from the tank. Quickly do your rearranging or redecorating, do a water change while you're at it and then slowly acclimate your fish back into the new water.

From: MoonCake - sick fish
I have 3 happy goldfishes for more than 2 years, but since few weeks ago, the biggest one stopped eating and preferred to stay on the bottom of the tank. His scales are perfect, and the water is filtered, clear and changed regularly. It is very unusual that he refused to eat because he normally eats lots and always swims happily. The only thing I haven't cleaned for a long while is the gravel and the bottom of tank. How do I know if he's just spawning or actually has parasite or something on him? Thank you in advance.
Response: Sometimes fish will not accept food for a few days after spawning. The reason they won't accept food is usually because they are not hungry due to the fact they just ate their eggs. Watch the fish closely and look for any signs of disease. Read the article on sick fish for more info on possible diseases if you fear that your fish is sick. You should definitely be checking your water parameters (ammonia, nitrite, nitrate and pH) and vacuuming the gravel on a regular basis while performing your water changes.

I have recently purchased a 5 gallon tank and put 2 gold fish a betta and a pleco in there. I changed half the water the first week and now after 12 days have cleaned the tank out. This morning my betta died and it looks like my gold fish has a white covering on him. Can you please tell me what im doing wrong? Thank you.
Response: Your aquarium has not completed the Aquarium Nitrogen Cycle. Your fish are being severely stressed due to high ammonia and nitrite levels. Study up on the nitrogen cycle, get a freshwater test kit and perform frequent water changes until this cycle completes.

From: Donna
I'm always reading how you shouldn't put "any" other fish with them... well, Butch is about 9 inches long and 4 years old. He is the center of my 55 gallon tank. I've never fed him goldfish food because I think it clouds your water. Instead I feed him tropical fish food. He is a big personality in our household of pets and eats tubifex worms out of my hand now. Butch lives with rosy barbs, 4 angelfish, 3 gouramis, 1 large and too cute for words parrot cichlid, and a well fed plecostomus. I'm building this larger home for butch slowly. He's been in this tank for about 5 months. It just goes to show if your BIG enough NOBODY messes with you!!! It's the other fish that get out of his way. I did however have to take out my neon tetras.

From: Judy - tank smell
Our tank (32 gallon) seems to have an odor, what can we do? They are mostly species of the gold fish. Thanks!!
Response: They are heavy polluters and require frequent water changes, at least 25% once a week in a tank of 32 gallons. If you're using activated carbon in your aquarium filter you will need to replace it every 2 weeks or so. If you're not using it, activated carbon may help with the odor.

From: Afton - goldifish with tropical fish
It's really unwise to put tropical fish in the same tank as them. Most fish you see in the store that are not goldfish are considered tropical. They need to be in water that is about 76-80 degrees Fahrenheit, while they need to be in water that is around room temperature- 68-70 degrees. Sure, they can survive in higher temperatures, but they'll be a lot happier if you keep them properly.

From: Peggy - pond
Two years ago, my husband installed a four tiered pond for me. Total water volume is approximately 1500 gallons, and there are 3 levels of bio-filtration. We are fortunate enough to have well water, and I do bi-weekly partial exchanges. Thick beds of anacharis provide oxygenation and nutrition, and act as nurseries for the orandas and koi (kept separated by walls and waterfalls). The whole thing is covered with its own lanai to keep out our fish-chomping feathered and furry friends. I bought the red caps when they were half-dollar size, and they've tripled in size! (their 'caps' are now half-dollar size) The koi were bought as fingerlings and are now 10-16" long. My ponds are also home to several apple snails, whose eggs are a great food source, a large pleco, and probably a trillion mosquito fish. (magnificent little jewels themselves) They are a lot of work but they return such a feeling of peace.
Response: Wow - that setup sounds awesome.

From: Sheilagh - swim bladder
If you have a goldfish with a swim bladder problem, definitely feed it a couple of frozen peas, thawed of course and chopped fine. Make sure they eat it and they should recover within a couple of hours. After a month I got my first fish, the one swam upside down for a month. I finally feed it some peas, and it recovered within an hour.

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