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What Kind of a Tank Do You Really Need for a Goldfish?

The Best Fish Tank for a Goldfish

Goldfish are an incredibly popular fish that are widely available in most if not all pet and aquarium stores as well as being very affordable to purchase that I thought it necessary to write about what I feel is the kind of tank you need for a pet Goldfish. It never ceases to amaze me how Goldfish and Betta fish (Siamese fighting fish) are poorly taken care of at local pet stores that I feel it important to give some insight into how to better take care of these living creatures.

Goldfish like every other fish you bring home to keep as a pet should be kept in a size appropriate aquarium where they can live a happy and healthy life. Always treat your pet fish with the same love and care you would with any other pet. Which part of, is giving your Goldfish enough living space to live and thrive.

The aquarium rule of thumb for matching fish to the correct size of aquarium is to allow approximately one inch of fish per gallon or 3.78 liters of water in the tank. This rule of thumb works fairly well most times.

The only issue I have with it is that an inch of a larger fish like a Goldfish is quite a bit different than an inch of a smaller aquarium fish like a Neon Tetra. This means that the biological load these two different fish have on your filtration system is different.

This also means you can get away with having more inches of the smaller fish in the same sized tank than you would of the larger fish.   

To decide on what kind of tank you need for your Goldfish you must consider a couple of things.  

  • How many Goldfish along with other fish will you want to have in your aquarium?
    • This point and the next one tie together very closely. Before you purchase an aquarium you must decide on how many fish you will want to keep. Once you know this number then go to point number two.
  • How big will your Goldfish grow?
    • Now that you know how many fish you want in your aquarium you should find out how big they will be once fully grown.
    • Most Goldfish kept in smaller size aquariums will never really get any bigger than five to six inches. Compared to when kept outdoors in a pond or very large aquariums some species of Goldfish can grow as large as 12”.

So if you still aren’t sure what kind of size of tank you should get to keep Goldfish let’s think about how many Goldfish could be kept in a 20 gallon or 75 liter aquarium. If you are going to have Goldfish only then in a 20 gallon you could put 4 fish assuming they will grow to about five inches each. If you find a species that stay smaller somewhere around three or four inches then five fish would be ok.

If you think you might end up adding other cold water fish then account for how big they are and will grow to be.

Chances are when you see the prices of a 20 gallon versus a 30 gallon you might opt for the larger aquarium. If that’s the case then you could easily keep six to seven Goldfish in a 30 gallon tank.

However maybe you just want a couple of fish and not a large aquarium to take care of. Let’s assume you want to know what size of a tank for just two Goldfish. You could purchase a 10 gallon / 37 liter aquarium which is the perfect size tank for two fish.

I am going to link to some Goldfish tanks for sale on Amazon that you can check out. Just a friendly tip for you. If you can afford to purchase an acrylic tank I would opt for one of those. I also have a recommended aquariums page you might want to have a look at.

What Kind of Water Do You use for a Goldfish?

Goldfish like any other fish should have clean cycled water. Yes they can tolerate swings in Nitrites, Nitrates and Ammonia from all of the water changes people do when they have them in bowls but it doesn’t make it right. I recommend if you are taking the time to take care of these pets properly then do yourself a favor and read my article on the Aquarium Nitrogen cycle which explains what needs to be done and how to do it.

  • So to answer the question of what kind of water do you need for Goldfish is a properly filtered tank which probably answers another question you just thought of as to whether a Goldfish needs a filter on its aquarium?

Do Goldfish Need a filter?

  • When you see a retailer with Goldfish in bowls without any filtration systems attached it doesn’t mean the fish does not require or prefer to have clean filtered water to live in. so do you need a water filter for a Goldfish? There are two answers in my mind.
  • 1- Yes you should have a filter running if you plan on having a tank with other fish or maybe live plants that can tolerate cooler temperatures and if you want to have healthy fish.
  • 2- No you do not need a filter if you plan on doing daily water changes of approximately 25% of the water each day.
  • My recommended way to go is to have a filter running at all times and performing 10 to 15% water changes weekly instead of daily.


Do Goldfish Really Need a Heater?

This answer depends again on what your plan is for your tank. Are you going to keep only Goldfish? Is the aquarium in a location that gets especially cold? Everyone with any experience with these fish will have an opinion for you and here is mine.

  • You can put Goldfish in a heated tank as long as the heated tank is not being heated for other fish or plants. If you are just turning on the heater enough to keep the water temp from fluctuating too much between night and day time temperatures in your home then that is what I would do.
  • Some owners might argue that Goldfish are cold/temperate water fish and can tolerate the swings in temp so it’s not such a big deal. Technically they are right however their fish are not as happy and healthy as a tank where there are not such swings in temp. I guarantee that.
  • Water temperature for a Goldfish tank should never go over 70 Fahrenheit (21 Celsius). Sixty Fahrenheit (15.5 Celsius) is probably warm enough.


Other Goldfish questions I Thought You Might Have

Okay so this article about what kind of tank does a Goldfish need got lengthy with all of the bonus material so I thought I might as well think of other questions you might have regarding the Goldfish. I came up with a few more to hopefully help you out.

Can Goldfish Live in a Fish Bowl Without a Filter?

  • Sure as long as you do daily water changes.
  • Make sure not to over feed.
  • Also consider that a fish bowl is just not large enough for a Goldfish to live happy and healthily. It is cruel in my mind to do this.

How Many Times a Day do You Have to Feed a Goldfish?

  • Feeding your Goldfish in the morning and then around supper time should be enough.
  • As with feeding any fish make sure you feed the fish just enough so they eat and either none or very little food falls to the bottom of the tank.

Do Goldfish Need a Light?

  • Surprisingly this is a valid question I have heard in the past. I think it came about because people are used to seeing Goldfish in bowls and typically fish bowls do not have canopies and lights.
  • Yes you should have a light on your Goldfish fish tank. Cycle the light to be on approximately 8 to 10 hours a day.

I really hope this information has helped you figure out what tank is best for your Goldfish. When it comes down to it just use some common sense and think about the living creature you are going to house as a pet. Fish deserve to be treated just as well as any other pet you might have.

Also remember that a fish 99% of the time comes from a very large body of water in the wild so will need some space to survive. Some fish are bred in captivity so never experienced the wild however this should not stop them from being in a sizable aquarium.

Related Posts

What Goldfish Can Live in a 10-Gallon Tank?

How to Tell if Your Goldfish is a Boy or a Girl?

The Origins of Goldfish: A Fascinating Journey Through History

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