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How Many Fish Can You House in a 30-Liter Biorb? Tank Suggests & FAQs

Sarah Psaradelis

By Sarah Psaradelis

actual use of biOrb Halo 30

BiOrb aquariums come in all shapes and sizes, but all BiOrbs are on the smaller side, making them nano aquariums. This aquarium is quite small, at around 6 gallons, which makes it suitable for one male betta fish—given that it has a heater and filtration system.

This sized aquarium is not suitable for many other species of fish because it’s too small. However, it can hold other aquatic creatures, like shrimp, that are able to thrive in small aquariums.

If you are looking to stock your BiOrb with aquatic life and are unsure what to put inside it, then this article is for you.

Can You Keep Fish in a 30-Litre BiOrb?

Fish can be kept in a BiOrb aquarium if the fish species is better suited for smaller aquariums.

While you can keep many species of fish in this sized aquarium, they will not be happy or thrive. Most fish species grow quite large, and they require lots of space to swim freely. 6 gallons is too small for many species of fish and is way below the recommended minimum for many of the most popular fish in the aquarium hobby—including goldfish, cichlids, gourami, tetras, and bottom-dwelling fish.

The BiOrb is a beautiful aquarium that usually includes a lighting and filtration system in the design, along with a sphere-shaped design to enhance the view of the aquarium. Although these types of aquariums look good in our homes and can fit into small spaces, it is important to stock the aquarium appropriately according to the species of fish’s needs, minimum tank sizes, and health.

It would not be a good idea to place a goldfish that grows up to 10 inches in size on average in a 6-gallon aquarium, though it would work for small fish, like bettas. According to Dr. Krista Keller, an exotic veterinarian at the Veterinary Teaching Hospital in Urbana, betta fish require a minimum of 5 gallons in tank size.

Although there are plenty of small fish species in the aquarium hobby—such as popular schooling fish, like tetras, who need to be in groups of six to eight (or more), as they are a social species—it would not be enough space to maintain these fish in a 6-gallon aquarium. Such fish may fail to thrive in such a contained environment.

biOrb Halo 30 Aquarium with MCR Lighting - 8 Gallon

The 5 Reasons Why Tank Size Is Important for Fish

1. Space to Swim Freely

The size of the aquarium is the most important consideration when choosing fish. This is because fish will likely live most of their life in it, and if it is too small, then a range of issues can arise. The size of the aquarium will directly impact how well your fish will live in its home since they have nowhere else to go. These intelligent creatures need enough space to swim freely, and enough water volume to grow to their full adult size like they would in the wild.


2. Minimize Stress

Many fish show signs of stress from being kept in a poorly sized aquarium, such as jumping, erratic swimming, lethargy, and even showing less interest in exploring their environment because there is not much to explore comfortably. Fish that create a high bio load with their waste products will also make the aquarium’s water parameters unstable, meaning that all the ammonia, nitrites, and nitrates in the aquarium water can fluctuate.

neon tetra
Image by: Joan Carles Juarez, Shutterstock

3. Maintain Better Water Quality

Fish naturally produce ammonia from their waste, and other factors such as fish food can also affect the ammonia levels. Now, the ammonia levels are very important to keep below 0.25 ppm, as even the smallest trace of ammonia is lethal to fish.

The smaller the concentration of water is for a fish with a high bioload, the more maintenance you will have to do, and the more fish deaths you may face by trying to control the ammonia levels.


4. Space to Grow

Most fish that you get from a pet store will not yet be their full-adult size, so they will require a large aquarium with enough space to grow over the next few years, as well as for clean water to grow in.

It is easier to purchase the right size aquarium for your fish from the start, rather than having to continuously upgrade your fish’s aquarium to fit their size, especially since some fish may grow slower in smaller aquariums.

Small fish tank aquarium with colourful snails and fish at home on wooden table. Fishbowl with freshwater animals in the room
Image by: Ja Crispy, Shutterstock

What Fish Can Live in a 30-Litre BiOrb Aquarium?

There are not many species of fish that will thrive in a 6-gallon aquarium. As mentioned, it can be a good home for one solitary male betta fish, as bettas are beginner-friendly fish that need an aquarium larger than 5 gallons. Make sure that you can fit a heater into your BiOrb aquarium, as bettas are tropical fish that need heated water.

lots of guppies swimming
Image by: underworld, Shutterstock

Best Aquarium Life for a 30-Litre BiOrb Aquarium:

  • Male betta fish
  • Guppies
  • Small species of snails
  • Neocaridina

You can also keep a small school of guppies in a 6-gallon BiOrb aquarium, or stock it with invertebrates, such as snails like ramshorns, bladder, or nerite snails. You can also place neocaridina shrimp in the aquarium instead of fish.

It is possible to keep both a snail and betta in a 6-gallon aquarium, as long as the filter can keep up with the bioload for good water quality.

If mixing aquarium life, you can keep one betta fish, in a group of 4–6 guppies in a 6-gallon aquarium. If there is plenty of coverage in the aquarium from live plants, you can keep the betta or guppies with a snail or shrimp. However, it is not a good idea to mix both guppies and bettas in a small aquarium because of their size.

tropical fish 1 divider

Final Thoughts

The 30-Litre BiOrb aquarium can make a great home for one male betta fish or a small group of guppies. You can also add small species of invertebrates, such as snails or shrimp, into the BiOrb aquarium, either on their own or as tank mates for the guppies or betta fish.

Make sure that you have a heater in the aquarium, as both guppies and bettas are tropical fish, and some species of shrimp are too. Once you have cycled this nano aquarium, you will get to enjoy the enhanced beauty of the design that comes with the BiOrb aquarium.


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