Goldfish Bowls for Beginners

The standard goldfish bowl with its iconic bubble shape has been for years the go-to home for a new pet goldfish. It’s an image that almost everyone associates with a first time fish owner. The reason for this is due two factors. The first is a common misconception people make by associating the small size of a goldfish bowl with it being easy to maintain. The other reason is that the a common goldfish is inexpensive and unfortunately it’s easy for people to not put a high value on the life of one. In the event it dies by improper care of an inexperienced owner, they can simple go purchase another one for less than a dollar.

And in fact many pet goldfish don’t live as long as they should (which should be many years not months) because of improper care. Two common mistakes include overfeeding and infrequent water changes.

Goldfish Bowl Small


Minimum Bowl Size: Warning

A basic rule on the amount of living space your goldfish needs to stay healthy is 10/15 gallons (38-57 liters) or so per every one fish. Some people say you need 20 gallons per goldfish but realistically, not everyone is going to have a 20 gallon goldfish bowl with just one fish in it? They can in fact survive in a smaller size tank, but, it can stunt their growth and potentially shorten their life-span if you never upgrade to a larger living space as the fish grow. Additionally, a small bowl will require a lot more maintenance to keep the bowl clean and the goldfish healthy. Read about the Nitrogen Cycle or the next beginner post on Goldfish Bowl Water for more info on water quality.

Oxygen Levels Matter

The more goldfish you have in a tank, the more oxygen that is required to keep them healthy. Try adding an air pump to agitate the surface of the water or place some live aquatic plants into the bowl since they give off oxygen too.

The best solution on maximizing oxygen in the water is to follow the rule of the greater the amount of surfaces area, the more oxygen in the water. For this fact, choose a wide goldfish bowl over a tall narrow one.

If you have the classic bubble shaped goldfish bowl, don’t fill it to the top since filling it to the top doesn’t provide the most surface area. Understand that more surface area is better than more water when it comes to your goldfishes health. If you fail to provide enough oxygen your pet can suffocate and die.

Do you need a bigger tank?

While we recommend at least a 10 gallon aquarium, we understand that not everyone can afford to upgrade to that right away or don’t have the space. Therefor, we feel it’s important that an owner gets the largest tank that they can afford. Any upgrade in the size of bowl is a step in the right direction. Take a look at the following options and see if they are a good solution to your current situation.

Recommended Upgrades

Iconic Bowl Shape 2.75 Gal
1.8 Gal Bowl-Tank
3-Gal Aquarium
5.5-Gal Aquarium
10 Gal Aquarium Kit

How to Clean a Goldfish Bowl

If you choose to use a goldfish bowl over an aquarium tank or outdoor pond, you will have to change the water almost daily because all goldfish in general produce a lot of waste and ammonia. By adding a layer of small gravel and a few living plants will help keep the water clean longer.

If are thinking about adding an algae eater, you will need to provide it space to live and grow too. You will also need to keep the water around 77F/25C, which is too warm for for goldfish ideally prefer. For these reasons, don’t add an algae eater. It’s not necessary anyways.

  1. To clean the water take out 50-75% of the goldfish bowl’s water and replace it with clean water that contains no chlorine. You can add a few drops from a dechlorinator to remove any chlorine from the water.
  2. If you are careful and act quickly to do the water change, you can probably leave the goldfish in the goldfish bowl you are cleaning. During this time you can scrub off any algae with a clean rag with no chemicals or detergents in it. We recommend an algae scrubber that you can get from your local pet store.
  3. Lastly and importantly, add a drop or so of water dechlorinator (Read the instructions on the bottle for exact measurements).

Note that a little bit of algae in a tank is a good thing. It adds oxygen into the water and provides a good source of snack food for your goldfish.

Goldfish Food

There are dozens of types of goldfish food on the market today and they come in a variety of forms and ingredients. Goldfish are omnivores which means they eat both plants and animals. However, they are mainly herbivores and shouldn’t only be fed animal products. Many hobbyists only buy and use one brand of goldfish meal and their pets live long lives. However, by mixing in several types of diet options, it ensures that the fish get a well balanced diet.
multi color fancy goldfish

Diet Options

Forms of goldfish food come in:

  • Flakes
  • Pellets
  • Wafers
  • Sticks
  • Animals/Plants

Processed and prepared as:

  • Dry food
  • Freeze-dried
  • Frozen
  • Living
Ingredient that are found in these forms and prepared types of food:

  • Tubifex worms
  • Brine shrimp
  • Blood worms
  • Krill
  • Plankton
  • Mysis
  • Shrimp
  • Cyclops
  • Daphnia
  • Mosquito larva
  • Algae and plants
Buy Fish Flakes

Buy Granule Food

How Much per Feeding

Goldfish are cold blooded which means they don’t need as much food as warm blood creatures. Since gold blooded animals don’t need to use energy to heat themselves up, they can go much longer without being fed. A fish could go a week or longer without eating. They will be hungry but not starving. A fish won’t shrivel up and die, but, they will stop growing during that time. When it finally starts eating again, it will begin to grow. Underfeeding is rarely the cause for concern, it’s overfeeding that causes the most problems. Often those problems include constipation and swim bladder problems.

Here is the rule of thumb for feeding; only feed them as much food as they can eat in 2-3 minutes. Over feeding can be fatal because goldfish are opportunistic scavengers and will continue to eat as long as there is food in the tank. This can lead to a burst intestine. That means they die. Over feeding will not make them grow faster; it is more likely to kill them. If you want them to grow, give them plenty of space to grow and maintain the health of the tank.

How Often to Feed

There is no clear answer to this question. In the wild, these fish eat tiny meals throughout the day and are healthy. Smaller meals more frequently are easier on the digestive tract. Small meals include a few flakes or pellets per fish. Observing behaviors during feeding time will help owners know if their pets need more food. If the goldfish appear to still be in a frenzy when all the food is gone, they might need a bit more next during the next feeding. It’s important to observe all of them individually to see if they are getting their fair share. That’s good goldfish care advice to follow.

Lionhead goldfish

Sick Goldfish

Don’t attempt to pick up or handle your goldfish because it will rub off the protective slime coat layer which helps the fish stay healthy.

Constipation: Symptoms include the fish floating on its side on top of the water, or it has a swollen belly. The Cure is to add greens to it’s diet, Peas are a great food to include in their diet. It helps like a laxative. Live plants will also help with this problem.

Swim Bladder: Symptoms include an inability to stay upright. the goldfish might face downwards, on its side or even upside down. It is not to be confused with constipation but treating the goldfish with the same methods as stated above can help minimize the effects of swim bladder. There is no cure to swim bladder as it a genetics problem. read more about swim bladder disease

Ich or Ick: Ichtyopthirius Symptoms include white spots on the body or fins and sometimes rapid gill movement. Cure it by cleaning your tank entirely (to remove the parasite that may be growing) and contacting your pet store for for Ich medication. However, those can be rough on goldfish so try using salt at a level of (3 teaspoons per gallon). Not all fish can handle this so make sure you only treat your goldfish.

Ammonia Poisoning: Symptoms of this include black and burned looking skin, especially on the tips of the fins. The first thing to do is to immediately perform a water change. You might then add a medication that helps promote healing of the protective slime coat. Next, buy an ammonia test kit to help you know when you need to change the water. Often in a bowl, you will need to change the water a few times a week or more.

Goldfish Facts

Quick Fact

  • 43 years is the record for the longest life span of a goldfish.
  • The maximum length of a goldfish is 23 inches.
  • Goldfish can’t close their eyes.
  • They do in fact sleep, just not like you and I do.
  • Goldfish do Not have a memory of 3 seconds; it’s more like three months.
  • You can train a goldfish to memorize colors and shapes.

Related Content

group of common goldfish


Q: How much can a goldfish weigh?

A: Fully grown goldfish can weigh up 10lbs (4.5kg) but that is rare. However, it’s not unrealistic for a goldfish to be 5lbs (2.25kg).

Q: Do goldfish have ears?

A: Goldfish do have ears but not like you and I. They have internal ear bones called an otolith that can feel vibrations. Avoid tapping on the glass since it will stress or even kill them.

Q: Do goldfish have lungs?

A: Goldfish do not have lungs. Goldfish breathe by drawing in oxygenated water through its mouth. It then closes its throat and forces the water through gill openings where the oxygen in the water is absorbed (inhales) into the fish. The water is pushed out through the gill openings, taking with it the (exhaled) carbon dioxide and ammonia. The gills in fish are the equivalent of lungs in humans. Oxygen gets inhaled through tiny membranes in the lungs or gills and CO2 (and ammonia in fish) is exhaled.

Q: What is the coldest water temperature a goldfish can survive in?

A: The common goldfish can survive in an outdoor pond where water temperatures dip down bellow 40*F (5*C). They will go into a semi-hibernation by sitting, not really moving much and not eating down at the bottom where the water is warmest. Some pond might even freeze over during the winter and the goldfish still survive through to the spring.

Q: Can you water your plants with dirty aquarium water?

A: You can water your house plants or garden plants with your dirty tank water. The nitrates and fish waste in the water are a great fertilizer for your plants.

34 comments on “Goldfish Bowls for Beginners

  1. I have a gold-fish and a betta put together in a small bowl with no extra decorations. The betta keeps on chasing the gold-fish and is it good for him like will it keep my gold-fish in stress??
    How many times do I have to change the water if a gold-fish and a betta are put together??
    Are any extra accessories required for the betterment of both??
    Any suggestions will be obliged for..
    Thank You

    • A betta should not be kept in the same tank with goldfish. You really should have two separate tanks. Bowl water should be changed daily. Decorations and a gravel substrate are good to make the fish feel more at home and less stressed. A water conditioner is also recommended to remove chlorine from the water.

  2. Hi..this article is indeed a great insight for the beginners..thanx alot.. i seem to have a doubt and i guess its a peculiar case. I have two goldfishes and i feed them twice-thrice daily but the problem I face is that one of them gulps up the entire food without letting the other one to even take a bite, fair share for that matter seems to be a distant thought.. quite a few times i have tried to pacify the bigger one and give the smaller one food but it doesnt take notice and even if it does, shows no interest and before its too late, the bigger one haves it. I am concerned about the smaller one as it has not been eating since 4 days. Kindly help me..What do i do?

    • Goldfish can go over a week or more without eating so there should be no reason for concern there. You may want to separate them for feeding until the slow one starts acting more like a goldfish.

  3. Hello,I am a beginner for fostering fish and having a new pet.i own 10inch glass bowl with 4 gold how should I maintain and keep them healthy…Please give info

    • You should read all the articles within the Goldfish Bowl section of this site but for starters, change the water daily and use a dechlorinator each time you do that. Also don’t over feed them. They only need a few flakes each per feeding.

  4. My 2 daughters won a goldfish from a block party. I have been reading like crazy on how to take care of them. My first mistake was getting a one gal. tank for the both. One is about 2 inchs long, the other 1 1/2 inch. I use bottled spring water for the tank because we live out in the country with hard water. The started kit I bought came with a water that still nessesary to use with the spring water? Right now I put just 4 drops in with the water. There tank also has gravel and one plant for oxygen. They are rarely at the top of the tank..mostly just at the bottom or middle. Also how long can I keep them in a 1 gal tank together? I would like to upgrade but whats the smallest gal. I can get for both because I don’t really have a ton of space right now. would it also be ok to scoop out 5o% of the water to replace with new water every 2-3 days since I’m using bottled water?? Need as much advice as possible. Thanks

    • Goldfish are hardy and could probably survive in the hard water you have. If you switch to that water, mix it in lowly with the bottled water over the course of a few days. You will need to change the water frequently so that’s why I suggest using the tap water. Also, use the drops if you use the tap water, to remove any chlorine. A ten gallon tank is what you should get but in the mean time, you can get a 2-5 gallon tank for relatively cheap. The bigger the tank the better chances they will survive. Lastly, you can purchase a cheap water test kit to test for ammonia. If the ammonia levels are high, do a water change. best of luck. :)

  5. My goldfish just stays in one place (the top of the tank)doing nothing. He also never closes his this normal? Oh yeah and he won’t eat.

    • It could be that your goldfish isn’t getting enough oxygen or it could be that it’s not yet comfortable with it’s new surroundings. The open mouth probably isn’t an issue. To add more oxygen into the water, you can add a filter or make sure the water temp is cool around 70*f.

  6. My goldfish is always at the top blowing bubbles is it normal? … I have it and a female betta in a 5gallon tank with a filter and a few decorations … Also they both look like they are loosing their scales what should I do?

    • If the two fish get along and don’t fight with each other, the scale loss can be due to an illness or poor water quality. That said though, I wouldn’t be surprised if they were nipping at each other. The water might not have enough oxygen in the water and so your goldfish hangs out at the top. Usually, Betta fish blow bubbles constantly so some of those bubbles can be from him. To add more oxygen into the water, try adding a small filter or bubbler. Also, change the water often to keep the ammonia levels down.

  7. My understanding is that some fish make bubbles in a collection in their tank to form a “bubble nest” to put eggs in. I assume this is in preparation for mating even if there is not another fish around.

  8. Today, I rescued a fish from the toilet in my dorm. I’m not sure what kind of fish it is. It looks like a goldfish, but i’m not completely sure. Should I worry about any germs that the gold fish may have picked up or anything like that? (how can I even be sure its a goldfish?)

    • Lol, I’m not sure if this was a joke or a legit question. If it’s brown, I don’t think it’s a goldfish. Umm but take a look at the section on identifying goldfish breeds. I don’t think you need to worry about the germs if you used clean water in the tank you put it into and not used any toilet water. why would anyone put a live fish into the toilet? Good on you for saving it though!

    • It’s hard to say why and it’s likely not a problem at all. it could be that it doesn’t feel secure and so it’s sticking to the bottom. Do you have decorations for it to hide amongst? Having a few decorations will make if feel safer and this might be enough to get it swimming around

  9. Sometimes my goldfish don`t feel well so I put him in a glass of water and make the water bowl fresh then I put him back in the bowl.

  10. Sometimes my goldfish “blows bubbles” at the surface. The bubbles stay at the surface at the edge of the bowl. What are these and why does my goldfish do this?

    • If your goldfish is always at the surface blowing bubbles, it could be a sign that your water needs more oxygen but if it only does it occasionally, It’s probably nothing to worry about. You can increase oxygen by keep the water temp cool around 70*f, adding an air pump to agitate the water surface or add a few aquatic plants.

  11. I want to buy one goldfish, but I gonna get a small plastic tank with the coloured cover, is plastic ok tho? Does a fish need pebbles?

    • Usually if you buy it from a pet store, the plastics should be aquarium safe. In the tank you want to get, I would only get on goldfish. Yes the like pebbles and plants or things to hide in or around. If you can, get a small (micro) filter for the tank too. best of luck :)


    • That’s good that you change the water every other day. If you just have a bowl, if you add another goldfish, you will probably need to change the water everyday. What I would do is buy an ammonia test kit and test your water, if with one goldfish, the ammonia levels don’t get to dangerous levels a day after you change the water, then you might be able to get another one. Honestly though, I would stick to one goldfish for your small bowl. Eventually your goldfish will grow and there won’t be enough room for two.

      It’s also good that you are not over feeding your goldfish; you are cutting down on waste and in turn, your water will stay cleaner longer.

  13. My goldfish is in a bowl and is developing black spots. I just had one die which had the same problem. I change about 50% of the water every day. I feed it every other day, part goldfish food and part veggie, e.g. pea or broccoli. Why the spots and what is the treatment?

    • That could be ammonia burns or your goldfish trying to fight off an infection. Test the water for ammonia and continue your water changes. Also you can try to use a broad spectrum medication to treat a number of bacterial or fungus infections. see the all my goldfish illness posts in the Goldfish Aquarium section.

  14. If you want your goldfish to be happy DON’T put it in a bowl, buy a small aquarium for him !

    bowls are just too small for a pet, even for a fish.

    • I agree with that statement – bowls are usually too small for goldfish and a tank is much better. However, some goldfish owners do use bowls so I want to help them out by providing the best goldfish care advice I can give them. Like constant water changes and limiting how many goldfish you put into any given size of bowl/tank.

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