Important Factors to Consider When Choosing Fish For Your Aquarium

Installing an aquarium in your space makes it enchanting and a nice place to unwind. Watching fish gracefully swim about at the end of a long day might be the remedy you never knew you needed. Plus, fish are a great pet alternative if you are allergic to furry creatures like dogs or cats.

Choosing the right fish for your aquarium can, nevertheless, be a daunting task. While most people prefer colorful and animated breeds to make their tanks lively, there are other important details to consider.

It is best to understand them before you end up with an aquarium situation that is more than you bargained for.

Here are some key factors to keep in mind as you pick your fish.

Freshwater Vs Saltwater Aquarium?

What is the difference between freshwater and saltwater?

Freshwater fish are more resilient and are thus often recommended for beginners. They will not die on you if you forget to feed them for a day. They are also easy to find from freshwater bodies like local lakes and rivers.

However, in terms of colors and patterns, they are not as vibrant as their saltwater counterparts. Breeds like rainbow fish, goldfish, or tetras are still fascinating to look at though.

Saltwater fish are more fragile and less forgiving of neglect. For all their beauty and diversity, you will have to be prompt when it comes to maintenance. They require a proper chemical balance of water to thrive and most prefer hiding places like reef rocks.

That said, there are some breeds like Tangs, Dottyback, and Damselfish that are quite hardy and low-maintenance. Aside from fish, you could also add crustaceans in a saltwater aquarium.

Ideally though, if you are a first-timer, you would be best served by picking the freshwater fish. The ability to easily switch between the two options means you can always learn on the job and go for the beauty later!

Breeding and Growth

After a while, you begin to notice new stars behind your aquarium screen. That would be the result of your fish breeding. Some types of fish like Guppies breed at a very fast rate. So, if you are not willing to raise an entire school of them, consider getting only one gender.

On the other hand, if you are hoping that your fish breed, ensure that there is a conducive temperature for fish eggs to survive. This way, you can always be in control of the numbers and manage the feeding better.

Growth is a vital consideration in determining how many fish you can get for your tank. You also do not want to end up with a fish type that will outgrow your tank size.

Neon Tetras, for example, grow only up to about 2.2cm while Angelfish can grow to a length of approximately 15cm.

Based on this, you could have more tetras in an aquarium than angelfish. For all the options that you have, this is one of the most important factors to consider when making your choice.


It turns out that even in the fish planet, not all creatures get along. As such, it is advisable to establish whether the fish types you have chosen are compatible. Take Betta fish, for instance.

They protect their territory quite aggressively and tend to fight fish that resemble them. Angelfish are equally feisty and tend to eat small fish in the tank as they are omnivorous. 

In contrast, some fish types are less aggressive and co-exist well with others. Firefish, clownfish, Green Chromis, or Talbot’s Damsels are highly recommended as mellow types of saltwater fish.

For a tranquil freshwater aquarium, consider Platies, Rainbowfish, or Neon Tetras. Introducing some fish breeds all at the same time may also help improve compatibility. New additions sometimes stir aggression where there was none.


The most fundamental part is ensuring that you keep the aquarium clean. Ensure to change the water as often as recommended while taking the necessary precautions.

Make an effort to also invest in quality maintenance equipment such as filter media and sterilizers to keep your aquarium working optimally. You can find such products at alongside lots of helpful maintenance information.

Additionally, before settling on a fish type, it would be prudent to learn their feeding habits. There are plant eaters like mollies and voracious carnivores like Royal gramma basslet.

Feeding times also vary as some fish are nocturnal and will only come out of hiding for food in the night. Aim for a type of fish whose feeding habits you can easily maintain.

Tank Size

The more fish you would like to have, the larger your aquarium has to be. This rule of thumb similarly applies for fish that require to be bred in a school. If you isolate such fish from their mates, they would get lonely and not cope well.

Size also plays a role in the health of your fish and how they get along. Larger tanks are less cramped and thus there is less in-fighting over territory or food. Moreover, they provide adequate room for growth. 

The catch, however, is that large tanks cost more to install and maintain. You may also feel overwhelmed if you are a first-time owner. Consider starting with a small manageable size and learning the ropes before getting an upgrade. Alternatively, you could choose to hire a professional to come in regularly to do the maintenance.

The Bottom Line

When you weigh all the factors involved in choosing the ideal fish, it may feel like an extreme sport. Still, do not let that dissuade you from your quest to set up an aquarium.

Once you get the right fish and understand their needs, it is all smooth sailing from there. Fortunately, it is also not a decision cast in stone. You can always change your mind and get a different variety of fish if you wish.

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