Community vs One Species Fish Tank – 9 Pros and Cons

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Should you set up a community tank or a one-species one? The eternal anguish of the future fish keeper.

The answer clearly depends on a variety of factors, including:

  • How much free time you have – Community tanks will require more maintenance and monitoring, especially if you have multiple fish species inhabiting the same space. If you lack time to care for a community tank, a one-species aquarium may be the better choice.
  • The fish’s size – Larger fish will require more space. Some may even need 50 gallons or more of water to feel comfortable and remain healthy in the long run. This means that mixing multiple fish species or even keeping multiple fish of the same species would be very difficult.
  • The number of fish – If you love having multiple fish, preferably from different species and strains, a community tank is right up your alley.

But what are the differences between the community and the one-species tank? Also, what pros and cons do each present?

Let’s have a look!

What is a Single Species Tank?

Just as the name suggests, single species aquariums are specialized towards accommodating one fish species alone. As you may already know, different fish species have different needs, and it’s often difficult to accommodate them in the same environment.

Single species aquariums eliminate this problem. You will only need to set the tank’s parameters to meet one species’ needs. The alternative would be to consider each species’ optimal parameters and try to find the middle ground. Fortunately, many aquarium fish species share similar environmental preferences with slight variations here and there.

Another reason for people choosing single species tanks over community aquariums would be a sense of identity and order. Some fish keepers prefer keeping one fish species for a sense of uniqueness, selective breeding, or simply because they love that species over any other.

Guppy owners, for instance, prefer keeping guppy-only tanks since guppies offer impressive diversity and variety via their coloring and patterns. They are also prolific breeders, capable of filling their environment fast. Not to mention their potential for creating profit via selective breeding.

What is a Community Fish Tank?

Community tanks are environments that hold multiple different fish species. These are generally peaceful, calm, and friendly creatures that can get along with a variety of different species.

Community tanks are usually ideal for resilient species that can adapt to a larger range of environmental parameters. It’s also essential for all species to prefer similar living conditions for the aquatic world to thrive. This means some research is necessary before acquiring the fish to make sure they are compatible.

Some species may be incompatible with others or prefer vastly different living conditions. Some of the crucial factors to consider when setting up a community tank include:

  • Fish’s size – In nature, bigger fish will see smaller fish as prey. The same happens in enclosed environments like a home aquarium, with a notable mention – the situation is even worse. At least, in the wild, the smaller fish has more room to run and hide. In the tank, not so much.
  • The fish’s aggression – Not all fish are peaceful, and not all are aggressive. At the same time, some are generally peaceful but can become territorial and aggressive, especially during the mating phase. Aggressive fish will never get along, and neither will aggressive and peaceful fish.
  • Environmental requirements – Some fish need more space for themselves, have different dietary requirements, and may prefer different water temperatures than others.

Pros and Cons of Single Species Fish Tank

So, what are the advantages and disadvantages of setting up a single species fish tank?


  • Ease of accommodation – It’s easier to satisfy the fish’s needs when you only have one species to worry about. This will allow you to set up the ideal water parameters, ensure optimal aquatic design, and improve the fish’s comfort. This makes single species tanks more fitting for novice fish keepers
  • Ease of long-term care – Having one fish species will allow you to become accustomed to its biology, behavior, and preferences, ultimately leading to greater ease of care. This is another reason why single species tanks are so popular among beginners, minimizing the risk of accidental mistreatment.
  • Allows for more effective selective breeding – Selective breeding refers to breeding fish with the goal of obtaining specific features and traits. The process is easier to apply when you have one fish species that you can monitor, breed, and manipulate to obtain optimal gene structures.


  • Monotony – No matter how impressive and diverse the fish species is, it’s still the same fish. Guppies, for instance, differ wildly in terms of coloring, size, and patterns. But they’re ultimately guppies with some variations here and there. For this reason, single species tanks can get boring after a while.
  • The need for larger aquariums – This is not always the case, but it can be. If you like a larger fish species, you can’t have too many specimens in the same tank. Consider the Oscar fish, which needs a 55-gallon tank for itself. It’s unlikely that you will manage to accommodate 3-4-5 fish in the same environment. Community tanks are different since you can pair the Oscar with smaller fish in the same setup and get the best of both worlds.

Pros and Cons of Community Fish Tank

The pros and cons to consider before setting up a community fish tank in your home:


  • Higher diversity – If you like more diverse tanks with a variety of fish species of different colors, sizes, and shapes, community tanks are for you. There are a few limitations when it comes to setting up a community tank. So long as the fish species are compatible in terms of environmental parameters, diet, behavior, and size, you can add them to the mix. Community tanks offer a more impressive sight and have a higher potential for long-term entertainment.
  • More interesting opportunities – Keeping a community tank may open the door for a lot of interesting opportunities, especially in relation to selective breeding. Maybe you begin to take a liking to a specific species and subject it to selective breeding. With multiple species available, you will also have multiple options at your disposal.


  • Beginners, beware – Community tanks are in no way fitting for novice fish keepers due to the avalanche of information necessary to ensure the environment’s stability. You have multiple fish species, each with its own requirements and needs. In this context, even minor mistakes can have devastating consequences. Inadequate feeding, for instance, may lead to health issues or ammonia increase, poisoning the water and killing the fish. Some species may also become aggressive towards others, resulting in bullying, injuries, and even death. These are issues best left to more advanced fish keepers who can minimize the damages.
  • A pricier hobby – Community tanks tend to demand higher financial efforts in the long run. This is also due to having to manage multiple fish species in the same environment. Depending on the community’s needs, this increases the risks of disease, various tank decorations, plants, and substrate changes.

Community Fish Tank Ideas

When it comes to setting up a stable and sustainable community fish tank, the sky is the limit. You have endless options at your disposal, only limited by your imagination. Here are several useful concepts that you can put to great use:

  • Guppies, swordtails, platies, honey gouramis – These species are close in size (between 2 to 5 inches in length) and share similar environmental requirements. They are all omnivorous, prefer tropical waters, and thrive in freshwater conditions with a stable day-night cycle. They are also friendly and acceptant of other fish species roaming in their space.
  • Otocinclus catfish, bristlenose pleco, cardinal tetra, and harlequin rasboras – These species are also compatible with behavior, diet, and water requirements. The bristlenose pleco, for instance, is an herbivore and thrives on algae, plants, and some occasional vegetables and spirulina. He will keep the tank clean along with the otocinclus catfish who shares its dietary preferences.
  • Betta, neon tetra, kuhli loach, fire rasbora – If you want variety, color, and a thriving and impressive aquatic environment, this setup is your best option. All these species will bring something visually striking to their habitat and complement each other in virtually all areas.

Species-Only Tank Ideas

If, instead, you’ve decided to opt for a species-only tank, your job is easier, to begin with. There is virtually no limitation to which fish species you can focus on, so long as it’s domesticated. You even have access to several shark species that are known to thrive in captivity.

If you’re a beginner, I recommend sticking with some hardy fish that are adaptable and easy to care for. These include guppies, platies, bettas, tetras, and even the common goldfish. These species are adaptable, resilient, and easy to care for, with minimal downsides.

Once you’ve become accustomed to caring for one fish species, you can upgrade your tank to a community setup.


Whether you prefer community tanks or go for the safer, single-species setups, you still have to take necessary precautions along the way. Make sure to provide your fish with an adequate diet and ideal living conditions.

Regular water changes are a must, along with setting up a stable environment to keep your fish healthy and thriving in the long run.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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