Should I Keep Tropical Fish or Cold Water Fish?

Updated on August 1, 2019
Hope Alexander profile image

I'm interested in pet fish, and I enjoy offering advice to aspiring fish owners.

A cold water Oranda on the left, and a tropical Betta (Siamese Fighting Fish) on the right.
A cold water Oranda on the left, and a tropical Betta (Siamese Fighting Fish) on the right.

Newcomers to the fish-keeping hobby will often mistakenly think that it is better to keep cold water fish such as goldfish because they don't require a heater, and the fact that they don't require a heater seems to imply that they are easier to keep than tropical fish.

The opposite is true. Yes, tropical fish will require that their water is kept somewhere between 20–25 degrees Celsius depending on the species, but tropical fish are almost certainly a better bet for the beginner. Why is this? There are several reasons.

1. Cold Water Fish Require More Space

The major reason why I would recommend tropical fish for a beginner is the fact that cold water fish need much more room than tropical fish. A 20-gallon tank is the recommended minimum for just one goldfish, whereas in a tropical setup with adequate filtration, you could have up to three or four medium-sized fish such as Angelfish and a few little shoaling ones like neon tetras in the same sized tank.

Tanks Stunt the Growth of Goldfish

Cold water fish are better kept in an outdoor pond than an indoor one, though you can always raise goldfish and koi indoors for the first few years of life and transfer them over to a pond when they are of sufficient size. If allowed to grow to their full size, even a garden variety goldfish will reach 12 inches in length. Common goldfish types include the common goldfish (obviously), the Comet, the Shubunkin, the Lionhead, the Oranda, the Veiltal, and the Fantail. These are undeniably beautiful fish, but it is cruel to keep them in tanks which stunt their growth.

2. Cold Water Tanks Need More Filtration

All fish types will require adequate filtration, usually in the form of an external or internal filter. Under-gravel filters are being phased out by many fish-keeping stores as they are viewed as being less effective than modern canister, hang on back, and internal filters. Cold water fish such as goldfish are very messy fish and will require excellent filtration if their water is to stay clean.

Clean water isn't just an aesthetic consideration; it is a requirement for healthy fish. Fish wastes are high in ammonia, which is extremely toxic to fish. A good filter system will contain bacteria that convert ammonia into nitrates, and nitrites into nitrates. When setting up a tank for the first time, you will need to cycle your tank, preferably without fish, to build up these bacteria before you put fish in the tank.

3. There Are a Wider Range of Tropical Fish

All fish will also need water that is pH appropriate. Goldfish tend to prefer a neutral pH, while tropical fish have a wider range of pH requirements depending on species.

There are a much wider range of tropical fish species available to the aquarist, and though they do all have their own particular traits and needs, if you are unwilling to go to the effort to monitor water quality, do frequent water changes, and familiarize yourself with the needs of your fish, then any fish is probably not suitable for you.

Whether Tropical or Cold Water, Fish Require Complex Care!

Fish used to be sold as easy care pets, but the reality is that to keep them well, and keep them healthy, they take a great deal more care than your average cat. If you are getting a fish for a child, then be aware that the costs associated with it may actually outweigh those associated with your average family moggy, who simply needs good food, a few vaccinations, flea and worm care, and a warm lap.

Fish Needs

Fish require all the following:

  • decent-sized tank (not one of those little pet store sold things which are too small to house anything but a few tiny neon tetras or be used as hospital tanks)
  • filter
  • heater
  • air pump
  • water testing kits
  • substrate
  • plants or plant substitutes
  • décor to hide in
  • a whole lot of love and attention

Fish-keeping is an incredibly rewarding hobby, but it also represents a not insignificant investment of time and money.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.


    0 of 8192 characters used
    Post Comment
    • profile image

      Rita griffiths 

      7 months ago

      I love my koi and tank fish but the goldfish inside the house are so so dirty so what the best fish to have warm and cold tanks


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)