How to Choose a Perfect Fish Tank Size for Your Little Pet Fish

Choose the perfect Fish tank according to your fish pet
By Garrison Hickles Updated

As a novice fish keeper, you may have a query about choosing suitable fish tank sizes for your little aquatic friends. However, some aquarists ignore the fact and select the wrong aquariums for water species, which may create trouble for the breeds. So, whether you are a beginner or an expert fish keeper, get proper suggestions from experienced aquarists before selecting a small, medium, or large tank size along with other setup requirements.

There are thousand or more fish and other water species in the world that vary in their sizes, and they need specific tank size to dwell. Choosing the wrong size may affect them adversely, as we have mentioned above.

Along with the sizes of the fish breeds, the temperament or behavior of the fish also matters a lot while selecting an aquarium for your pet fish. Moreover, if a fish is aggressive in nature, then you always need a big fish tank, and for peaceful breeds of small size, you can select medium or small-sized fish aquarium. Now, let’s have an overview at some popular fish, their temperament and their tank size requirements in the given table:

Large-Size Fish Tanks

There are multiple fish breeds, among them, the large-size breeds are needed to be kept in large aquariums where the specifications are mentioned below:

Fish NamesFish SizeMinimum Tank Size (Single Fish)Tank Size (For Group Breeds)Filled Weight of Fish Tank
Silver Arowana2-3 inches250 Gallons500 Gallons2500 lbs.
Butterflyfish8.7 inches125 Gallons250 Gallons1400 lbs.
Garibaldi12 inches 100 Gallons200 Gallons1200 lbs.
Oscar11-15 inches 60 Gallons150 Gallons900 lbs.

Medium Size Fish Tanks

The medium size fish should always be kept in a medium-sized aquarium where they can keep medium-sized fish breeds. Look at the specifications below:

Fish NamesFish SizeMinimum Tank Size (Single Fish)Tank Size (For Group Breeds)Filled Weight of Fish Tank
Rainbow Shark6 -7 inches50 Gallons80 Gallons200 lbs.
Royal Gramma3 inches 30 Gallons100 Gallons300 lbs.
Killifish1-6 inches 20 Gallons60 Gallons700 lbs.

Small Size Fish Tanks

It is not necessary to bring spacious tanks in your house. Just bring small-sized aquariums to keep small fish breeds.

Fish NamesFish SizeMinimum Tank Size (Single Fish)Tank Size (For Group Breeds)Filled Weight of Fish Tank
Neon Tetras1.5 inches 10 Gallons25 Gallons120 lbs.
Dwarf Gourami2 inches 6 Gallon15 Gallons110 lbs.
Betta Fish2.25 inches 5 Gallons15 Gallons100 lbs.
Goldfish4 inches 3 Gallons10 Gallons200 lbs.

Common Mistakes Done by Beginners in Selecting Right Aquarium

Some beginners often make common mistakes by purchasing a small fish tank due to inadequate space in their home and office. This makes the fish violent, suffocated, and aggressive, which are the adverse sources of their health downfall. Along with that, the fish keepers also do several other mistakes, which can harm the fish. Hope you don’t want to see your little friends in trouble. So, try to avoid some mistakes mentioned below:


Purchasing Fish Tank without Knowing the Size and Temperament of the Fish

Novice fish keepers really don’t know what is the specific size of a fish and chose a wrong aquarium for them. Definitely, as mentioned above, acquire knowledge about the temperament, height, width and tank size of any fish breed you want to keep. This complete information will really help you in giving comfort to your swimming-companion by avoiding the mistakes.


Making the Fish Tank Overcrowded

Generally, fish enthusiasts keep too many fish together in a fish tank, which may create chaos among the breeds and make the water dirty.

To get rid of these crucial problems, try to keep fewer water species in a single tank whether the aquarium is large or small in size. Also, make the living place of your tiny buddies spacious, so that they don’t feel suffocated and irritating.


Purchasing Fish and the Aquarium in the Same Day

Some aquarists make a great mistake by buying their favorite pet fish and the tank on the same day. But do you know it can really trouble you, and confuse you in setting the tank just in a single day?

To avoid this mistake, buy a fish jar with two or three fish breeds and keep them in the clean distilled water of a jar. After a day, purchase a fish tank and set water, decorations, plants, gravels and other necessary objects in the tank. Once the tank is decorated and ready to keep your cute swimming-companions, keep the fish breeds in the aquarium by holding them with a soft fishnet.


Mixing Wrong Water Species

Many fish keepers don’t understand the compatibility as per the temperament of the fish breeds and keep wrong companions together in the water, which result in fights, bloodsheds or even death.

If you really want to avoid these negative effects then know about the temperament and compatibility of each pet fish you are breeding, and also acquire an idea about the suitable tankmates for your buddies before you plan to keep different water species together.


Blindly Trusting Pet Stores for Selecting Tank

Usually, fish keepers have too much faith on the seller of the fish pet store because they think shop keepers are never wrong, as they have complete knowledge and experience about every fish they sell.

No, it’s completely a wrong belief; the pet store-keepers may have very specific knowledge about some breeds, but it’s not possible to keep 100% information about all the breeds. So, before having a hobby to keep fish, try to get plenty of knowledge by researching fish from the internet and books where complete details about water species are mentioned. Don’t trust blindly on others, and first, try getting suggestions from experienced aquarists before you start breeding different fish.


Frequently Changing Place for Different Fish Breeds

This is a very bad habit of changing fish tanks or fish jars frequently on a weekly or monthly basis because this can disrupt or irritate some breeds who don’t like shifting their living place, as they are comfortable in living at the same place for a long time.

Remember, they are not like human beings who love changing their homes. So, you should set an aquarium properly before keeping fish in a tank. Moreover, you can add necessary decors or objects while cleaning an aquarium. If you want to change a fish tank then you can change it once in a year.


If your fish tank gets scratched due to the small space inside or you want to add more water species, you can change or replace a medium-sized tank with a large tank if required.


Keeping the Aquarium in a Wrong Place

Some aquarists keep their aquarium near the sunlight or near window, but the harsh air and sunlight may really harm the fish.

If you want to provide comfort to your little friends then keep the aquarium in a cool place where no one can disturb the water species.


Keeping the Lid of the Fish Tank Open

There are several fish that are aggressive and the best jumpers. Remember, they will always try to jump out from the fish tank and if they jump high, they then whether the tank may fall down and some fish can come out.

Therefore, be careful in fixing the top-most lid of the fish tank carefully, and also keep the tank in a big spacious table, so that the fish cannot come out. Moreover, never keep a tank at the edge of the table, because it can easily fall down and your little buddies may meet an accidental death because of your fault.

Results of Choosing Wrong Fish-Tank Size

Keeping large and aggressive tempered breeds in small tanks can be dangerous for their life and the other companions in the same place as mentioned above. It may result in fighting, bloodsheds, irritation, health issues, and many other problems. Therefore, figure out the appropriate space or collect more information about your pet breeds before keeping them in an aquarium. You may have a look at some significant problems that fish face while kept in a small aquarium or in a congestible living place:


Undersized Growth

When a large fish breed is kept in a small fish tank, it does not grow properly and feels choked in the aquarium. The unhealthy living condition is the primary reasons for their stress and other health issues along with color-fading. Therefore, try to know about the breeds and their required space related to the size and temperament for their smooth growth with a healthy life.


Downfall of Lifespan

The large fish will also become ill, and their lifespan will get reduced if you provide an unhealthy environment to them by keeping them in a small aquarium.

Veterinary doctors also say, if a fish is not comfortable in an aquarium then it may get affected with multiple life-threatening diseases, stress, and panic attacks. So, fish keepers are suggested not to restrain the little water species which can make them unhappy. Stress is the reason of heart stroke and internal organ failure of sensitive fish.


Behavioral Disorder

As mentioned previously, if less space is given to a large breed fish then it will get affected by anxiety and that may result in aggressive nature, irritation, annoyance, fighting mood and many other negative behavioral disorders. These types of mood-fluctuations will also harm the other aquatic species in the fish tank. So, plan accordingly before choosing fish tank size for particular breeds.


Difficult to Clean

You will find a significant amount of uneaten food and fish poops, which can make the tank water dirty. So, a large fish tank is needed because keeping a small aquarium and making it over-crowded may be unhygienic because it’s hard to clean small fish tanks. Therefore, bacterial and fungal infections spread quickly in the water and make it poisonous.


Unbalanced Water Parameter and Temperature

A little amount of water in a small aquarium can make the pH scale, hardness and temperature of the water unbalanced, and make the home of the fish an uncomfortable place to dwell. Moreover, the oxygen level of the water will be unstable which will obstruct the fish to breathe properly.

What are the Suitable Places to Put a Fish Tank

You have to choose a suitable fish tank size but along with that never forget to select a proper place in keeping the aquarium. Take a look at a few appropriate places for placing a tank:

  • Peaceful Place – You can keep a fish tank at your bedroom or at a large drawing room at a corner. Make sure small children don’t go such rooms at any cost because they may accidentally push the tank, and it may lead to a pathetic death of your favorite pet fish.
  • Cool Temperate Place – Fish and other aquatic species don’t like staying in the hot temperature, so try to keep them in a cool place where sunlight and heat do not disturb them.
  • Low Noisy Place – Generally, fish don’t like noise pollution because they are peaceful in nature. So, if you want to make them comfortable, then keep your fish tank in a silent environment.

The comfort and safety of your pet fish are the mandatory things that you should provide to them. So, don’t ignore the proper size requirement of your fish breeds, and provide a happy living place to them.

Tips from Expert Aquarists

Before you purchase an aquarium and choose a proper fish tank size, follow these quick tips:

  • Decide what type of fish breeds do you want to adopt – large, medium or small water species.
  • Know about the nature of the fish before selecting an aquarium.
  • Try to identify whether you need a thick or thin glass aquarium for different fish.
  • Don’t keep aquariums in the room of your children or any crowdy places because it may fall down once it is pushed by anyone.
  • Purchase another small fish tank during the reproduction or egg fertilization process of different fish.
  • Choose rectangular-shaped fish tank rather than the square one because rectangular aquariums help the fish to survive long and swim freely, similar to how they swim in their natural habitat.

Get More Information about Petting Your Fish by Choosing Appropriate Tank

There are several fish in the entire world and different breeds need specific places to live. So, along with this article, you can also know about other topics as follows: