This article was co-authored by Craig Morton and by wikiHow staff writer, Janice Tieperman. Craig Morton is the CEO of Aquarium Doctor Inc. based in Huntington Beach California and servicing Orange County, Los Angeles County, and the Inland Empire. With over 30 years of aquarium experience, Craig specializes in creating custom aquarium designs along with aquarium installation, service, and maintenance.
There are 19 references cited in this article, which can be found at the bottom of the page.
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When it comes to fishkeeping, some hobbyists abide by the “1 inch of fish per 1 gallon of water” rule. Other aquarium specialists, however, believe that fish stocking relies on several different things, like potential fish waste, the total amount of tank space, and your fish’s potential size and temperament. With the help of aquarium specialist Craig Morton, we’ll examine the most important factors to consider as you prepare your tank. We’ve also put together a mini cheat sheet for some common types of aquarium fish, so you can make an informed decision for your setup.
How many fish can you place in a fish tank?
A common suggestion is 1 inch of fish per 1 gallon of water, but this guideline may not be suitable for all aquariums. It’s important to consider your tank’s filtration capabilities, volume, and surface area, along with the fish you’d like to keep (e.g., whether they’re schooling fish or more independent).
Steps
How to Plan Your Tank
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Write a list of fish you’d like in your aquarium. Are you hoping to fill your tank with beautiful freshwater fish (like tetras), or are you eyeing a saltwater setup? Make a list of the fish you’d most like to have in your aquarium, so you can start narrowing things down.
- Do a little research online and see what types of fish other fish hobbyists have in their aquariums. It might help to seek out fish that are more beginner-friendly, like the common goldfish, barbs, angelfish, or cory catfish.[17]
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Choose fish that can thrive in similar tank conditions. There are lots of different fish out there with all sorts of feeding and environmental requirements. Once you’ve jotted down a list of fish you’d like to have in your aquarium, research the type of food and ideal living conditions they need. It doesn’t make sense to choose fish that have vastly different requirements.[18]
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Set a realistic tank maintenance schedule for yourself. Think about what an average week in the life looks like for you. What are your school/work commitments? Could you manage a weekly maintenance schedule, or does a low-key, monthly routine make more sense for your schedule? The more often you’re able to clean your tank, the more fish you can feasibly take on.[19]
- Aquarium specialist Morton suggests “changing 25% of the water every two weeks.”[20]
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Add your favorite fish to your aquarium first. Don’t add any other fish at this time—just give these new fish time to adjust and get used to their new home.[21]
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Test the nitrate levels over the next couple of weeks. Using a nitrate test kit, see how your tank fares in terms of cleanliness. Test your water a few times during this period, or at a frequency that makes the most sense to you.[22]
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Add new fish if the nitrate levels are 40-45 ppm or less. Once your tank hits 40-45 ppm, you need to change the water to help cleanse the aquarium’s ecosystem. If the water is below that threshold, feel free to add some new fish to your tank.[23]
- Once you’ve added new fish, test the water levels for another couple of weeks to see if they hit the 40-45 ppm mark. If they pollute the water too much, consider this the max threshold for your tank. If you’d still like to add more fish, consider upgrading your aquarium setup to something larger, or changing your water more often.
Community Q&A
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QuestionCan axolotls live with other animals?Aussie JCommunity AnswerMost choose to keep them separately as they require different conditions than most other aquatic animals.
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QuestionI have a foxface and the other night while watching him I saw a bug/parasite looking thing enter through his gills. The fish is still alive now. I was wondering how to get rid of that parasite?Titans - Gaming and moreCommunity AnswerTry quick ich X, it is a medicinal solution with a small amount of salt that is harmless to the fish, and should kill the parasite.
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QuestionHow many fish like harlequins can fit in a ten liter tank?cymbospondylus 846Community AnswerOne harley needs 5 liters so if you want to keep them you can only get 2 harleys although they are 5 cm.
Video
Tips
References
- ↑ https://www.fdacs.gov/Consumer-Resources/Recreation-and-Leisure/Aquarium-Fish/Aquarium-Fish-FAQ/Is-there-a-limit-on-how-many-fish-you-can-have-in-an-aquarium
- ↑ https://www.co2art.eu/blogs/blog/overcrowded-aquarium-why-less-fish-in-your-fish-tank-is-better
- ↑ Craig Morton. Aquarium Specialist, Aquarium Doctor Inc.. Expert Interview. 21 July 2020.
- ↑ https://users.cs.duke.edu/~narten/faq/hardware.html
- ↑ https://hgic.clemson.edu/factsheet/aquaponics-the-culture-of-fish-and-plants-together-in-one-system/
- ↑ https://www.aquariumcoop.com/blogs/aquarium/how-to-change-aquarium-water-correctly
- ↑ Craig Morton. Aquarium Specialist, Aquarium Doctor Inc.. Expert Interview. 21 July 2020.
- ↑ https://www.iowadnr.gov/About-DNR/DNR-News-Releases/ArticleID/1454/How-do-fish-breathe
- ↑ https://www.co2art.eu/blogs/blog/overcrowded-aquarium-why-less-fish-in-your-fish-tank-is-better
- ↑ https://users.cs.duke.edu/~narten/faq/hardware.html
- ↑ https://injaf.org/the-think-tank/adult-sizes-of-popular-fish-species/
- ↑ https://injaf.org/aquarium-fish/the-goldfish-section/what-size-tank-for-goldfish/
- ↑ https://vetmed.illinois.edu/pet-health-columns/betta-fish/
- ↑ https://www.aquariumsource.com/bottom-feeder-fish/
- ↑ https://www.aqueon.com/articles/schooling-fish
- ↑ https://www.aqueon.com/resources/care-guides/discus
- ↑ https://www.aquariumcoop.com/blogs/aquarium/10-best-aquarium-fish-for-beginners
- ↑ https://www.youtube.com/watch?v=nEgwOpEFnwo&t=5m38s
- ↑ https://www.youtube.com/watch?v=nEgwOpEFnwo&t=6m8s
- ↑ Craig Morton. Aquarium Specialist, Aquarium Doctor Inc.. Expert Interview. 21 July 2020.
- ↑ https://www.youtube.com/watch?v=nEgwOpEFnwo&t=6m21s
- ↑ https://www.youtube.com/watch?v=nEgwOpEFnwo&t=6m37s
- ↑ https://www.youtube.com/watch?v=nEgwOpEFnwo&t=6m55s
About This Article
To know how many fish you can place in a fish tank, follow the general rule that you'll need a gallon of water for every inch long your fish is. For example, a 3-inch fish would need 3 gallons of water just for itself. You should also take into account the types of fish you'll be keeping, since larger, aggressive fish will need more room than smaller ones. Moreover, you can put more fish in your tank if you choose species that like to swim at different levels, such as beta fish, which swim at the top. For tips on how to calculate how large your tank is, keep reading!
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