How Big Do Glofish Get?


Do you have a fish tank? The glofish is one of the most popular types of freshwater fish in America. These tropical fish are colorful and fun to watch, but they do need special care. Let’s find out How Big Do Glofish Get and what we can do to take proper care of them!

Please read on if you would like to learn more about these wonderful creatures!

How Big Do Glofish Get – A General Guide

If you want a colorful, diverse fish tank that’s not too big but still spacious enough to handle your favorite species of glofish or even small tetras, then it is important to consider their size when choosing tanks. So how big can they get?

Type of fish Size
Tiger barb glofish 3 inches
Danio fish: 2.5 inches
Glofish tetras 2.5 inches
Rainbow shark glofish: 6 inches

As you can see, we don’t think a 10 gallon tank is suitable for glofish farming. It would be best to get a 30g tank or bigger for the fish to thrive.

How Big Do Glofish Get – A Detailed Instruction

  • Danios

My favorite Danios are the ones with zebra and leopard prints. They’re little schooling fish that may grow to be 2 inches long and eat anything!

  • Barb

Barbs Are Among the Most Popular Aquaria Fish. They typically range from 2 to 6 inches (but people can produce glofish in lower sizes), making them ideal companions for many fish keepers!

Furthermore, these lovely creatures fluoresce under black light, and their dark vertical striping adds to their radiance.

  • Tetra

Tetras are schooling species with both short-finned and long-finned variations. The GloFish generated from this type of fish closely resembles Black Skirt Tetra, which has also been bred for similar coloring – these two species may cohabit happily without competing too hard against each other or any other tank residents!

  • Sharks

The newest GloFish sharks are related to the Rainbow Shark. These fish may grow 6 inches long and are semi-aggressive omnivores that consume both plants and meat!

How Many Gallons In Space Do Glofish Need?

The key to keeping your glofish happy is determining which type you have. Tiger barbs and rainbow sharks require at least 20 gallons, whereas danio/tetras require at least a tank of at least 10 gallons to thrive!

Anything greater than this size is also advised since these schooling fish can grow 2+ inches long. If you don’t have enough room and try to fit a bunch of 2.5-inch fish into a tiny tank, they won’t be able to breathe, swim, or develop. Isn’t it awful?

Understanding the water quality criteria and how big your tank may go before running into rooming or compatibility concerns is critical.

Can Glofish survive in a 10-gallon tank?

Glofish requires more area to grow. Therefore 20 gallons may be too little.

Tetra and Danio are little schooling fish, so pick the suitable tank size for them. In this situation, a 20-gallon tank is ideal since they’ll need plenty of areas to swim around in peace, but not too much space that your pet becomes lonely!

How many Glofish can a 5-gallon tank keep?

True, the tank size for these fish is modest. However, if you just want to keep one or two of them, you should be good!

But, once again, due to the schooling characteristics, they prefer groups of more than 5-6 individuals per school, so they can only survive with more pals nearby. Before going to glofish, we still recommend having a larger tank.

Read more: How Many Glofish In A 5 Gallon Tank

How many Glofish can a 20-gallon tank keep?

5-6 glofish can live happily in this amount of space! They will not only grow and have an average lifetime of three years, but you will also be able to maintain appropriate water conditions with ease.

Furthermore, all species will thrive in this tank if their spouses are also present. This size is ideal for individuals new to the aquarium hobby since you can easily adjust the water conditions, decorating, and the fish’s health.

Related Questions


Can a glofish live alone?

Glofish are not solitary creatures but must dwell in groups of at least 5-6. Since they match many different species in the same tank, you may offer them more.

What happens if I overcrowd my tank?

Crowding the tank with too many fish can lead to aggressive competition and starvation.

The best way is to keep only one or two types of small-sized freshwater creatures per gallon, so they have enough space for swimming around in between each other without bumping into you!

How many GloFish should be kept together?

Danios, tetras, and barbs are schooling fish, so you should get at least six of the same species to make them feel more comfortable and lessen aggression problems. Different colors are fine, so you could, for example, get one tetra of each color to form a school of six.

Tiger barbs are semi-aggressive fish that may attack other types of GloFish, so if you are a beginner fish keeper, we highly recommend keeping them in a species-only tank containing other tiger barbs.


How big do Glofish get? The size of a Glofish depends on the type and how long they have been in your aquarium. They will grow to about 2 inches after one year, but this may vary depending on their diet and tank mates.

If you’re considering adding Glofish to your aquarium, we hope this guide has given you a better understanding of how big they can grow and what setup is needed. Thank you for taking your time!

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