Small Tropical Fish: 21 Reasons why you should keep them!

If you’re thinking of setting up an aquarium in your home you need to think of a few things before going out and buying your fish tank. The size of the aquarium you’re thinking of buying will determine the size of fish you keep. Small tropical fish like Guppies and Neon Tetra are very popular for home aquarists for a number of reasons.

Aqua scape tank

Let’s take a look at:

21 Reasons Why You Should Buy Small Tropical Fish.

21. Value

Small freshwater tropical fish come in all sorts of colors, sizes, varieties and species. There are over 1500 popular small tropical fish to choose from. From the most popular fish that we all know and love like Guppy and Neon Tetra to the more unusual Killifish and Bumblebee Catfish.

All tropical fish have their advantages but keeping small tropical fish often outweighs many other fish when you’re thinking of setting up an aquarium. Many larger fish can cost a small fortune.

Enough to purchase a small, if not, a large home. A Platinum Arowana was sold for over $400,000 breaking the record for the most expensive tropical fish ever sold!

Compare that to half a dozen beautiful Cardinal Tetras for $12.

Betta fish are one of the most stunning fish you will ever see. These fish come in many different colors and varieties and sell anywhere from $5 – $50.

Still within most people’s price range for such a beautiful fish. As you can see small tropical fish offer much better value than larger more specialist fish.

20. Smaller aquarium

The size of your aquarium, or more importantly, the water volume that your aquarium holds will determine how many tropical fish you can keep.

There are some rules that people apply when considering how many fish can be safely kept in an aquarium. One inch of fish per gallon of water seems to be the most popular method.

We, however, simply go by the rule of not overstocking your aquarium. Build up the levels of fish slowly and enjoy going out and buying new fish at the weekend.

Once your aquarium is running smoothly and all the water conditions are perfect (we use a test kit like this one click here), then add fish very slowly which will give your aquarium time to adjust to the new inhabitants and your filter to break down harmful chemicals that come from the fishes waste.

Plus the fun part is going out and buying new fish. So why rush and buy them all at once? We love going to the aquarium store at the weekends as a family and choosing new fish.

If you add one fish per week until your aquarium looks good, it can keep you occupied for quite some time.

Just remember, less is more with aquarium fish. Rocks, plants, filters all take up space and reduce water volume so the amount of fish you can keep is reduced. A 15-20 Gallon aquarium is a good starting point and will hold 10-12 small fish without any issues.

19. Variety

With many larger species of fish like Tiger Oscars or Tiger Shovelnose Catfish they grow extremely large and are very aggressive therefore the variety of fish you can keep with them is reduced.

Read our Tiger Oscar Tank Mates article to see what we mean.

With smaller tropical fish you have a bigger selection of fish that can live in the same aquarium. This is often known in the hobby as a ‘Community’.

Tiger Oscars need a large aquarium and cost more to keep and feed.

A community aquarium, filled with a wonderful variety of fish showing all their different colors and behaviors, is one of the most attractive and special parts of keeping a home aquarium.

I have sat for hours watching my 4 foot home aquarium packed with Angelfish, Catfish like Corydoras Sterbai, Tetra, Mollies and Clown Loach.

They all swim at different levels of the aquarium and have something different to offer. You never know where to look sometimes. One minute you’re watching a molly feeding on the surface, next minute you’re watching a clown loach coming out from a rock and chasing around the bottom of the tank in search of food.

If you’re looking for an aquarium that is full of color, character and is fun to keep, then you need to consider setting up a freshwater community aquarium with small tropical fish.

18. Upkeep

Small tropical fish produce less waste compared to larger tropical fish like African Cichlids. Fact!

They still need regular maintenance and water changes and their aquarium water conditions could still be affected by what you do. Overfeeding is the number one cause of poor aquarium water. Little and often is the best practice when it comes to feeding your fish.

Larger fish need more specialist and messier meaty foods which often pollute the aquarium water.

Read our article on Color enhancing fish foods, all natural and good for your small tropical fish.

Small tropical fish should be given a variety of foods including flake fish food and live foods like Bloodworms. Variety in their diet is the key to a successful home aquarium. Some foods even bring out their natural colors.

Water changes should be performed once every two weeks and we suggest changing 25% of the aquarium water.

17. Nano Aquariums


Nano aquariums have become very popular in the past few years and are used in a craze that’s exploded recently and that’s Aquascaping.

Check out our 14 Best Aquascaping Fish Guide Here!

Aquascaping is the art form of recreating underwater scenes using plants and rocks and small tropical fish. Fish are often not the main attraction in these aquariums but they do add another dimension to the scene.

Fish like Neon Tetra and Harlequin Tetras are used in large numbers, often in their hundreds, to create a large school of fish. If you’ve ever wondered what the difference is between schooling and shoaling read our article linked here for more details.

Nano aquariums are not suitable for novice aquarists due to the water conditions being unstable. Small 5 Gallon aquariums are difficult to maintain perfect water chemistry. However, if you made an aquascaped aquarium from a 10-20 Gallon aquarium you’ll be fine. That amount of water is easier to control and keep within safe parameters.

16. Schooling

What is schooling and why do fish school? Wikipedia explains it really well.

Schooling and shoaling is a kind of collective animal behaviour
by fish. Any group of fish that stays together for social reasons is said to be shoaling, and if the shoal is swimming in the same direction together, it is schooling.

Quote from

Here’s a good video from Youtube to explain in more detail. Rachel O’leary explains it in one of her videos and does a much better job of explaining it than we can.

15. Colors

It’s fair to say that larger tropical fish usually come in duller colors (all the large fish enthusiasts are now screaming at their screens). They often display one or two colors which can look attractive but pale into comparison when compared to a show-stopping Guppy or Betta Fish.

Take a look at some of the colors below on these Betta fish and I’m sure you’ll agree they are incredible.

Many smaller tropical fish display beautiful colors which are even more apparent when mating or courting. Their spectacular colors can be even more enhanced by feeding them color enhancing foods and live foods which will bring out their colors for all to see.

The range and variety of colors is simply stunning and you’ll have no problem choosing some amazing little fish for your aquarium if you set up a community aquarium.

betta fish
Betta fish come in many different colors and are perfect small tropical fish for beginners

14. Community

What is a community aquarium? A community aquarium is a collective group of fish that live together in the same aquarium peacefully. They don’t always come from the same region or are of the same species but all require the same water conditions to thrive.

Within a community freshwater aquarium, you can have different swimming levels of fish. Surface swimmers, mid-level and bottom swimmers like Catfish.

Having a variety of fish that swim at different levels adds an extra dimension to your aquarium and ensures there’s always something to look at and enjoy.

A peaceful aquarium can be achieved if you select the fish carefully. Your fish outlet will guide you on the best fish that live together. We have a guide that you can read which will also help you make the right choice when purchasing new fish to live in your tropical community aquarium. Here’s the best tropical fish for beginner’s guide.

13. Breeding

Small tropical fish are sometimes easier to breed. This is not always the case but some livebearing fish like Mollies and Guppies often breed in a community aquarium.

Their young don’t always survive as other fish will eat the young fry but if you’re quick enough you can net the baby fish and put them in a fry-container within the aquarium and keep them there until they are big enough to be released back into the aquarium.

Large tropical fish can also be breed in a home aquarium but usually pairing these fish is difficult due to the size of the aquarium needed.

Smaller tropical fish will usually find their own partners and breed without warning. The joy of waking up and seeing baby fry is one of the attractions of keeping small tropical fish.

12. Feeding

feeding fish
Everyone loves feeding their fish

Feeding small tropical fish is easier than larger species. Larger fish often need more meaty products and even live feeder-fish. Feeder-fish are usually small goldfish that are fed to large species. Not something we agree with but some larger fish will only accept live foods.

Small tropical fish will live happily on dried flake food and freeze-dried foods like Brine shrimp and Bloodworms.

Variety is the key to their success. Food for small tropical fish is inexpensive and readily available. To find out how much it cost to set up, run and feed a small community aquarium read our guide here.

How much you feed your fish is very important. Just a small pinch of dried fish flake 3 times a day is fine. Then feed them a few different foods 2-3 times a week to add a bit of variety.

Some people also feed their fish certain vegetables like lettuce. Bottom feeders and Algae Eaters love this kind of food. Just remember to remove the leftover remains so they don’t pollute the aquarium water.

11. Reduce stress

It has been researched and proven that brightly lit and beautiful aquariums can reduce stress. Watching an aquarium for 10 minutes a day increases the feelings of relaxation, and decreases heart rate and muscle tension.

Children with special needs and conditions often find them relaxing to watch. Studies have shown that they focus better after seeing and watching aquarium fish peacefully swim around.

Children who name their pet fish often become more empathetic to other pets and people. My son has named his two goldfish after Fortnite Characters (I have no clue who they are).

If you’d like some suggestions for naming your fish read our 101 (ish) fish names article. You’ll find some great names on the list to help you name your fish.

The sound of the water running through the aquarium and filter is also an attraction to most people. Running water sounds have been used in relaxation methods for years and continue to be a popular way to relax and fall asleep.

10. They’re quiet

Smaller fish barely make a noise compared to larger fish that splash around and even move rocks and gravel in the aquarium.

The equipment used on smaller aquariums is often built into the aquarium which is much quieter and easier to maintain. Larger fish need bigger and noisier external filters and pumps to keep their aquarium clean. These are noisier and more obtrusive in a living room or workplace.

Most of the time all you can hear in a small freshwater aquarium is the gentle sound of the bubbling or gently moving water. Both of which, I for one, find relaxing.

9. Easy to keep

article on the cost of maintaining a fish tank.
Cleaning and maintaining a small aquarium is much easier than a large aquarium

A mixed community aquarium is easy to keep. Most fish sold for community home aquariums don’t need any special requirements and live and thrive in most aquarium setups.

The majority of fish sold today for life in a home aquarium have been bred in captivity and are acclimatized to life in an aquarium. They are hardier than their wild counterparts and are less susceptible to tropical fish disease.

Easy to keep does not mean you don’t need to check the water conditions or perform regular water changes but they are hardier and more prepared if there are sudden changes in water conditions.

This will give you time to react and rectify and issues before your fish suffer.

With some fish like saltwater fish, if the water conditions suddenly change, there’s a higher chance that your fish are in danger. This can often mean loss of life and sometimes a total wipeout of the aquarium inhabitants within hours.

Small community fish are hardier and easier to keep. Hence, most beginners and new hobbyists opt to keep small tropical fish at home before moving onto saltwater.

8. Rewarding

Seeing a beautiful aquarium is very rewarding. The time and patience you put into it will come back 10 fold and you’ll get pleasure from watching your aquarium day after day.

Watching your small tropical fish grow and often breed is very satisfying and plays a big part in why people keep fish for many years.

There is always a bump in the road with fish keeping in the first few years when you may experience issues like a break out of disease. But once you deal with that and get over the initial shock you’ll realize that keeping fish is very rewarding.

Likewise, nursing a poorly fish back to health is very rewarding. We set up a small 5-gallon aquarium where we treat any poorly fish separately, away from the community, to reduce the risk of spreading any disease throughout the aquarium

7. Perfect for beginners

Small tropical fish are perfect for beginners. Inexpensive and easy to keep they are the first choice for thousands of new fish keepers every year.

You can buy a small aquarium ready to just add water, wait for the water-cycle to complete and then add fish for under a few hundred dollars. These aquariums are great for children and first-time aquarists.

The water cycle is where bacteria needs to grow to stabilize nitrates and ammonia levels within the aquarium. It can take up four weeks to grow the necessary ‘good’ bacteria in a new aquarium but is well worth the wait.

Below are a few of our favorite small aquariums on Amazon:

Last updated on May 23, 2024 6:27 am

6. Aquascaping

Aquascaping has been around for many years but it is just coming into the public eye as one of the fastest-growing sectors of the hobby.

In an aquascaped aquarium you recreate underwater gardens and scenes from rocks and plants. You can then add a school of fish that will add depth to the scene.

Below are some amazing examples of aquascaped aquariums. These types of aquariums are not for the beginner as they often need C02, lights and other specialist equipment to get the full effect and make the plants grow.

Once you get into this part of the hobby you’ll be caught up in its popularity. The skills you’ll need to learn is like gardening underwater. The options and scenes you can recreate are endless.

Small tropical fish have their part to play in aquascaped aquariums without a doubt as they add movement, color, fascination and relaxation.

Well planted aquarium

5. Equipment

Fishkeeping equipment is much cheaper for smaller aquariums and that’s a fact. Larger fish tanks need bigger lighting systems and external filters with specialist filter media to cope with the waste that larger fish produce.

Smaller tropical fish need less expensive equipment which is easier to replace if they go faulty.

The expense of purchasing a small aquarium and all the gear needed to successfully keep tropical fish is much less compared to a larger aquarium and fish which can run into hundreds if not, thousands of dollars.

4. Water changes

fish tank water changes

The golden rule is to change 25% of your aquarium water every two weeks unless there’s an issue then more may be needed. 25% of a small aquarium is easy to carry out compared to 25% of a larger fish tank.

It is important to test your aquarium water weekly to verify good quality in addition to a bi-weekly partial water change of 25% to help reduce toxic buildup, remove debris the filter missed, and replenish the oxygen available to fish.

Adding clean, freshwater to your aquarium also replaces natural minerals to your aquarium which are essential for your tropical fish to thrive.

Just remember when performing water changes to use a De-Chlorinator which instantly neutralizes chlorine, chloramines and other chemicals to make tap water safe for fish.

3. Buying fish

where to buy your first pet fish
Choosing new fish is one of the best parts of keeping tropical fish

The best part of keeping tropical fish is taking a trip to your local pet store or aquarium shop and buying new fish for your aquarium.

We look forward to the weekend when all the family goes to the store to choose a new fish. We often spend hours together, choosing our next inhabitant for our community aquarium.

You can only stock a small amount of fish in a small aquarium so choose wisely and enjoy the quality family time.

2. Location

Small aquariums are easier to place in the home. They can even go in your children’s bedroom or small office.

Aquariums weigh a lot and large aquariums with rocks and gravel can easily weigh over 400 lbs for an average size aquarium. Ensuring the floor and stand are strong enough can reduce the locations you can place them and increase the cost of setting one up.

Small aquariums don’t weigh as much and therefore can be placed in more convenient or desirable locations in your home.

Never place an aquarium in direct sunlight and consider where you’re going to plug them into a power supply.

1. Fun

Fishkeeping is fun and very addictive. I have been in the hobby now for over 30 years and I still love going to the pet store and buying new fish. I also love it when my fish breed, often unexpectedly.

Feeding your fish is another fun factor. You can buy automatic fish feeders but I love to hand feed my fish and watch them eat. If you don’t enjoy feeding your fish you may be in the wrong hobby.

image of guppy
Guppies are one of the most popular small tropical fish to keep

Why You Should Keep Small Tropical Fish

Above are 21 reasons why you should keep small tropical fish over larger species of fish but in all honesty, we could have written even more.

Small tropical fish are bright and colorful, fast-paced, fun to keep and inexpensive.

Compared to many other pets you or your child could keep, they are easy to care for, don’t need to go for walkies and once you have invested and laid out the money for the tank and equipment they are inexpensive to keep month on month.

They are a good stress buster and many children especially children with special needs love them and find them very calming and therapeutic.

Benefits Of Smaller Tropical Fish

There are many benefits to keeping small tropical fish and the number one benefit in our opinion is the variety you can keep in one aquarium. Some larger fish tanks can only hold 2-3 species if you go for larger more aggressive fish.

Compare this to smaller tropical fish where you can have up to 20 different fish in an average size starter aquarium.

Is there a downside to keeping smaller tropical fish? Yes, you’ll find it hard to give each one a name. Also larger fish can be more interactive with their owners. I had a pair of Tiger Oscars that would feed from my hand and came to the front of the aquarium to greet me when I returned from home.

This won’t happen with a tank full of Neon Tetras.

Cost Of Keeping Small Tropical Fish

The cost of keeping small tropical fish is much lower than with larger fish. Fish food for a start is much cheaper. Larger fish need specialist foods which are not cheap.

Equipment costs are lower on the initial setup for smaller aquariums and repairing or replacing them again is much cheaper.

Running costs and electricity bills are lower with smaller aquariums. Lighting costs can be very high with large aquariums and especially saltwater aquariums.

Here’s a breakdown of the cost of keeping tropical fish.


  • How much does an aquarium cost for small fish? You can buy and set up a 10-gallon aquarium for less than $150 depending on the lighting and filters you buy
  • How long should aquarium lights be on for? 8-12 hours a day is normal and some people put them on a timer to control and mimic natural daylight conditions
  • How many times a day do you feed small tropical fish? 2-3 times a day providing them with a variety of foods including live foods is fine
  • How much do small tropical fish cost? This is a difficult one to answer as there are over 1500 species of small tropical fish to choose from. The average cost is $8 per fish. However, some specialist and rare small fish can sell for over $100
  • What filter will I need for a small fish tank? An internal filter or undergravel filter is fine for most small aquariums. If you want to keep as much space as possible try a hang-on-the-back filter or an external canister filter.

Conclusion: Keeping Small Tropical Fish

I know we are very biased when it comes to keeping fish compared to dogs or cats as pets. But we truly believe aquarium fish are wonderful pets and bring a family closer together.

There are pros and cons to keeping every type of pet and aquariums are no exception. That is one thing to remember! There are more pros than cons that’s for sure.

Peaceful, easy to care for, don’t need to go for walkies and don’t keep the neighbors up barking all day and night. That sounds like a great pet, Right?

Why not try setting up your fish tropical fish tank and let us know how you get on.