Goldfish Care: How to take care of goldfish

Goldfish care: How to take care of goldfish, including tank size

Care for your goldfish properly. Never keep them in a bowl!

Well done for taking the time to research proper goldfish care!

Jump straight to a particular goldfish care article using the links below.

Unfortunately, many people don’t bother to find out about proper goldfish care, and think that goldfish can simply be kept in small, unfiltered bowls. It’s one of the biggest mistakes new goldfish keepers make. Often, this isn’t the fault of the person caring for the goldfish, but the fault of pet shop staff.

The sad fact is that there are far too many pet shops still selling small bowls (some places have banned this, but unfortunately it’s still legal in many countries) and far too many ill-informed pet shop employees that give very bad advice to inexperienced goldfish keepers. This inevitably leads to poor goldfish care, goldfish living very short lives and some very unhappy fishkeepers.

So, whether this is your first experience of keeping goldfish, or whether you’ve made some of these common mistakes in the past: well done for putting the effort in to get it right this time!

The expert goldfish care guide…

Help I have a goldfish bowl cover

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1. What not to do: 12 mistakes new goldfish keepers make

Learn from other people’s goldfish care mistakes and avoid making them yourself, with this list of 12 mistakes new goldfish keepers make. Read more…

2. Essential kit: what you need to keep goldfish

To keep goldfish healthy and happy, you of course need the right equipment: essential kit such as a big tank, a filter and a supply of nutritious food. Check out our recommended products here and make sure you have everything you need!

3. Tank Size: Do goldfish need a big tank?

In order to take care of goldfish properly, you need to ensure that they have a suitable place to live. That means buying an appropriate tank. Goldfish need a lot of room so you should buy a big tank, not a small bowl. Read more…

4. Tank Setup: Cycling a goldfish tank 

What is cycling and why is it an important part of goldfish care? Find out what you need to do to prepare your tank water before you buy your first goldfish! Read more…

5. Tank Mates: Keeping other fish with goldfish

Can you keep other fish with goldfish? If so, what types of fish make suitable tank mates? Read more…

6. Filtration: Do goldfish need a filter?

As well as buying a big enough tank, you also need to ensure that your goldfish’s water is properly filtered. A wide range of internal and external filters are available and you need to pick the right filter in order to properly care for your goldfish. Read more…

7. Air pumps: Do goldfish need an air pump?

We’ve already found out that you should definitely add a filter to your goldfish tank. But what about an air pump? What is the difference between a filter and an air pump? And is an air pump necessary for goldfish? Read more…

8. Goldfish Food: What do goldfish eat?

Understanding what goldfish eat and what you should and shouldn’t feed your fish is an absolutely essential part of proper goldfish care. Feeding the wrong type – or the wrong amount – of goldfish food can be very bad for your fish! Read more…

8a. Floating flakes versus sinking pellets

What are the pros and cons of feeding your goldfish sinking pellets versus flakes that float on the surface of the water? Read more…

8b. Seasonal feeding of goldfish

In the wild, a goldfish’s diet will vary throughout the year as temperatures change and as breeding season is reached. So, what should you feed your goldfish in spring, summer, fall and winter? Read more…

8c. Feeding your goldfish treats

It’s important to offer your goldfish a balanced diet and feed them more than just flakes and pellets. In this article, we look at the various treat available to add a bit of variety to your goldfish’s diet. Read more…

8d. Frozen and live food

Like all animals, goldfish need a varied diet in order to stay healthy. Feeding your goldfish the same pellets or flakes all the time may mean they don’t get all the nutrition they need. So, why not try feeding them these live or frozen foods instead?  Read more…

9. Water Changes: How to change your goldfish’s tank water

Water changes are an essential aspect of proper goldfish care. In this post, we explain how often you should do a water change, how much water to change each time, and tell you some of the most common water change mistakes to avoid! Read more…

10. Lighting: Do goldfish need an aquarium light?

Lighting is certainly less important than feeding, tank size and filtration, but it is still an element of goldfish care that you should consider when setting up your tank. Read more…

Help I have a goldfish bowl cover

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11. Temperature: What is a suitable goldfish tank temperature?

What temperature is best for goldfish? How hot is too hot? How cold is too cold? And what temperature encourages goldfish to breed? Read more…

12. Breeding: How to breed goldfish

Goldfish breeding is not an easy task, but it is possible to breed goldfish in a tank or pond – it just takes good care, the right conditions and plenty of patience! Read more…

Read all of our posts on goldfish care? Then check out our top 10 goldfish facts!

  • Aaron Davis

    This really worked my goldfish lived 10 weeks already

    • TheGoldfishTank

      Thanks Aaron! We’re pleased to hear that our advice helped.

      Best of luck with your fish!


  • matthewl mayes

    thanks this really helped my gold fish he has lived for a 2 years nows

    • TheGoldfishTank

      Glad that we could help and well done for looking after your fish so well!


  • Monic

    thank you sooooooooooo much for all that information!

    • TheGoldfishTank

      No problem Monic! Glad to hear you found it useful! :)


  • kenzietomlinson99

    Wow thank you so much this is helping a ton!!! I own three comet goldfish and I was trying to figure out temps. and stuff like that thank you!!!! I do have one question I have an 100 gal. tank and I was wondering if I should get one more for schooling purposes???????? THANKS FOR THE HELP

  • kenzietomlinson99

    Wow thank you so much this is helping a ton!!! I own three comet goldfish and I was trying to figure out temps. and stuff like that thank you!!!! I do have one question I have an 100 gal. tank and I was wondering if I should get one more for schooling purposes???????? THANKS FOR THE HELP!!!!!!!

  • kenzietomlinson99

    Wow thank you so much this is helping a ton!!! I own three comet goldfish and I was trying to figure out temps. and stuff like that thank you!!!! I do have one question I have an 100 gal. tank and I was wondering if I should get one more for schooling purposes???????? THANKS FOR THE HELP!!!!!!!!!

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  • littlewolf

    Thanks this helped this the longest I’ve halved fish for and I love my butter common goldfish and blaze comet goldfish

  • eminem12

    i had to minnows in my tank and my goldfish fins was being eaten by the minnows so i took them out now my goldfish just sits on the bottom of me tank
    help me

  • totally newbie

    For the size of the tank, is it still 10gallons for every gold fish? Even if they are just feeder fishes? Thanks for your advice.

    • TheGoldfishTank

      Hi there.

      Yes, we’d say 10 gallons absolute minimum for any goldfish.

      There’s really no such thing as “feeder fish” – they’re all goldfish, all goldfish have the potential to grow to a foot long or more, and they therefore need plenty of room to grow.

      Hope that helps!


  • David Barker

    We got our goldfish 10 months ago at a County Fair for .10 ring toss. Brought him home 30 miles in my GF’s lap on my motorcycle. He’s doing great, getting bigger all the time and this website has really opened my eyes up. We did get a 3 gallon tank w/ filter and air pump after we had him for 2-3 months. got him out of the fish bowl! Thanks for the info..

  • Vivi.aka.Vienna_thegirl_

    My goldfish doesn’t seem very happy, he doesn’t swim around in his tank he just stays on the floor and moves a little bit. :(! Help plz

  • Vivi.aka.Vienna_thegirl_

    From Vienna McVei

  • Jamil Maali

    Plzz help me i have problem with ma gold fishes , the water was too dirty , suddenly one fish died , then i changed a 25% of the water , then the big problem is when i changed the water the fishes heads and tails started to convert into black dark color what is the reason , I’m scared pllllzzzz help me :( i trust u TGT i will show u a pic how :(

    • kirt

      This looks like a case of gill flukes. A parasite infection. There are meds available. Also raise your water temp up slightly to about 75ish for a few days along with the medication. And be sure to take the carbon out off filter while treating them.

    • turboBlue

      It could be ammonia burn. If your water was that dirty, changing it probably was a huge relief for them. The black can be healing. Change 25% of the water daily until everything evens out. Your ammonia, nitrites, and nitrates were probably off the charts! Remember, changing 50% of the water twice a week will keep your goldfish alive and healthy longer. Don’t just change the water when it gets dirty, change it way before then!

    • Kitty

      Hi I am sorry about your problem and your loss. Are any of your fish still alive? If so how often do you change the water?

  • Jamil Maali

    how can i send u the pic of ma fish plzz

  • Jamil Maali

    plz when i changed the water sth started to appear at the fishes ?

  • Nicole

    My black moor has clear bubbles on his scales that just appeared a few days ago. He has been hanging out near the bottom of the tank but that’s not uncommon for him. We have had him for approximately 16 months. We have 4 goldfish (of different varieties) in our tank that’s a 40 gal tank. They seem very happy and doing well but I’m concerned about the bubbles on the one; the others don’t have any. Any suggestions/input would be great!

    • Kitty

      Hmm I have owned goldgish and other fish for very, very many years and have never heard of that, maybe you could try talking to an educated person at the pet store, and remember change 20 to 30 percent of the water every few days and not to over feed them

  • Jess

    I am concerned from all that I have read that I have an overstocked tank. I’ve got 4 young (ish) fantails in a 47gal bow front tank. I use 2 filters rated for 75gal and have a air pump for a 60gal tank. I also do water changes with 40-50% every week.
    They have done awesome for about 6 months, but about a month ago I got a tiny weather loach that was a little too frisky at night and jumped out in less than a week. I’ve kept up with water testing and changes, but yesterday they started to have red streaks and spots on their top fins and by the base of their tails. I did a water change 3 days early with about 60% today.
    Do I need to treat with antibiotics? Are they overstocked? I read they could be stressed? What causes stress?

    • Kitty

      It depends on there size but, if they are still only an inch of two it is not over stocked.

  • Kitty

    Please help me!

  • Kitty

    I have 2 fantails, 1 is about a 1/2 inch the other is about an inch, I bleive my bigger fish isn’t getting enough to eat! How can I help my fish?

  • Maddie

    My sister has 2 black moor fish in a ten gallon. I need to know the recommended size for them. I know they won’t live long in the tank they’re in right now.