Last Updated: 2/12/09

Why Goldfish Bowls are Bad
How to Improve Upon a Goldfish Bowl
How to Clean Goldfish Bowls

Much of this list also pertains to other fish kept in bowls (the first item only applies to large fish).

• Common goldfish grow to 12 to 16 inches long with fancy goldfish growing to about half that. Unless the bowl is huge, the goldfish will eventually have little physical room in which to live. It is not true that a fish will stop growing if the container is too small. What in fact happens is that the fish becomes stunted and/or dies from waste build up before its time.
  
• Controlling water chemistry in a bowl is very difficult. The ammonia and nitrite will go up quickly especially in bowls that lack any kind of filtration. Water changes can only help so much. For more on water chemistry, see this page.
  
• Oxygen levels tend to be low without any aeration or filtration and with limited space. Goldfish can suffocate.
  
• It is very hard to physically clean a bowl or change the water. There is not enough room for a filter.
  
• Due to its small size, few things can be added to a bowl including animals and ornaments.
  
• Goldfish are bored in a small bowl with nothing to do.
  
• Goldfish rarely live more than a few months or a year in a bowl while they can 10 to 30 years or more in a proper setup.
  
• Bowls are prone to being spilled or breaking.
  
• Fish can jump out of an uncovered bowl.
  
• Bowls often have a low surface area to volume ratio which means low oxygen levels which can prove deadly.
  
• A fish bowl will almost never look or stay clean.

For more general reasons that bowls are bad, go to my fish care page.

Ok, so you know your fish is better off in something other than a bowl. So, what to do? If you can get an aquarium or pond, that is ideal. Goldfish should have 10 gallons each while young if possible. Of course, the larger the tank, the better. A 5 gallon tank is an improvement over a bowl for example. It is tons easier to keep fish alive in a fully functional aquarium than a bowl. Yes, it costs more but not a lot, and yes, it takes up more space. As far as time goes, it takes less than 30 minutes a week to tend to a 20 gallon aquarium. It may take at least 10 minutes to clean a bowl.

"I can't get an aquarium!" If for some reason, you have to keep your fish in a bowl, there are still a few things that you can do to improve the situation:

• Get a larger bowl.
  
• Add aeration. Adding an air pump with air stone that lightly aerates the water is the best thing you can do to improve the water quality in a bowl.
  
• Add a small filter. There are some small air-driven filters that can fit in a bowl.
  
• Change 50% of the bowl's water every few days or as needed. A water change at least once a week is really important in small containers. When you change water, be sure to added recommended doses of dechlorinator if you have city water. Adding a tablespoon of aquarium salt per 5 gallons can help goldfish. See here for more on salt.
  
• Adding some fake plants, gravel, and ornaments is good for places to hide but do not add so many that it is hard to clean the bowl or so that the fish do not have much room in which to swim.

Goldfish (and all fish) take time to adapt to changes in their water chemistry, especially temperature and pH. While many people do 100% water changes on bowls, that is not the best thing for the fish. It can be quite shocking. Anything more than a 50% water change is especially hard on fish and should only be done when necessary (emergencies for example). Here are my tips on how to clean a goldfish bowl (or most fish bowls).

For regular water changes:

1. Use a small cup like a Dixie cup to bail out half the water in the bowl.
2. Wipe down the sides of the bowl inside if needed using an algae pad or even a paper towel.
3. Prepare that same volume of water with fresh water. [You should at some point test your tap water's pH, hardness, nitrate, etc. to be sure it is safe. If unsure, you can purchase spring water or water from an aquarium store but you can usually use the tap water.] To that water, be sure to add dechlorinator if you have city water for the chlorine in there. It may also help to add some aquarium salt (a tablespoon per 5 gallons so much less for a bowl) for the volume of water that you are changing. Once you know the volume being changed, it is also a good idea to aerate the new water for at least 30 minutes with an air stone. See this page for more on water additives, types of water, aeration, and so on. Allow the new water to come to a similar temperature as what is in the bowl.
3. Slowly pour the fresh water in to the bowl.

For a more complete cleaning if the gravel and bowl need better cleaning:

1. Obtain a container at least a gallon in size that is fish-safe and has never been used with chemicals. A plastic bucket works well. If you have a cat, I use empty plastic cat litter buckets for all sorts of things; just wash them well with warm water before using them.
2. Remove any thing in the bowl aside from the goldfish that will be in the way if you try to pour the bowl out.
3. Gently pour the goldfish and half the water in to the bucket. If the bowl is large enough, you could net the goldfish or use a cup to catch him/her.
4. Cover the bucket with the goldfish while you work on the bowl.
5. Remove everything from the bowl and scrub it down. Do not over scrub as that will remove good bacteria. You can use a toothbrush (kept solely for fish cleaning).
6. Set the bowl back up. As in #3 above, prepare new water to replace what was dumped out. Put everything back but the goldfish in that half of the water.
7. Gently put the goldfish and unchanged (old) water back in to the bowl.

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See the master index for the fish pages.

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