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How Many Glofish Per Gallon? (Ideal Tank Size & Mates)

How Many Glofish Per Gallon? (Ideal Tank Size & Mates)

Glofish are beautiful and colorful fish that add an aesthetic touch to your aquarium. But many hobbyists are confused about how many Glofish to keep per gallon of water. If you are in the same predicament, then this article is for you.

How many glofish per gallon? You can keep them in groups of 5-6 in a 20-gallon tank. They are schooling fish and need at least a 20-gallon tank to thrive. 

We will elaborate on this in subsequent sections. Glofish are schooling fish, so need to be kept in groups in order to thrive.

How many should I keep in my tank? What would happen if the aquarium becomes overcrowded? For these and more answers, read on as this article will be a quantum leap for your glofish keeping hobby.

Recommended Tank: GloFish Aquarium Kit Fish Tank (link to amazon)

The Number of Glofish per Gallon

As mentioned earlier, the number of glofish in an aquarium should be decided by how many gallons of water your tank can hold. Let’s look at a breakdown of specific gallons.

Gallons No. of Glofish
5-gallon tank Not recommended (leads to poor health and aggression)
10-gallon tank Not recommended for rainbow shark glofish and tiger barb. Ideal for danio and tetra glofish
20-gallon tank 5-6
30-gallon tank Approximately 9
50-gallon tank More than 10

Glofish are schooling fish, therefore keeping them in a 5- or 10-gallon tank will lead to overcrowding and ultimately will result in poor health. Also, they can grow up to a maximum length of 2.5”. As such, although when they are still young it might seem like a good idea to keep them in a small tank, they will soon outgrow the space.

Another thing – you also need to make sure that the tank decorations do not take up too much of the swimming space. Ensure you keep a perfect ratio, to provide the right proportion of hiding and swimming space. Again, do not keep them in a group of fewer than 5 fish. 5-6 fish per group is recommended.

How many gallons do Glofish need?

Tiger barb and rainbow shark glofish need at least a 20-gallon tank, while danio and tetra glofish require a minimum of 10 gallons.

Why? They are schooling fish and grow to a maximum size of 2.5 inches. Imagine keeping five 2.5” glofish in a 5-gallon tank? Awful! Right? As such you need to aim for a minimum of 20 gallons for optimal health and, well … GLOW!

Anything larger than this is also highly recommended for keeping glofish happy.

Can Glofish live in a 10-gallon tank?

Well, yes they can. But this can lead to poor health and increases the risk of infections. Conversely, it is ideal for tetra and danio glofish. However, we do not recommend this size of tank if you plan to keep them together with tank mates. Larger tanks are ideal. You get the gist!

How many Glofish can be kept in a 5-gallon tank?

Honestly speaking, this tank is too small for glofish. Well, I suppose that strictly speaking keeping one fish would be fine – but if you plan to keep the recommended numbers, you are just barking up the wrong tree.

Again, they are schooling fish and can thrive in groups of 5-6. We don’t recommend keeping your colorful friends in such a small tank because, in the end, it will be a kick in the teeth. And we are certain you are not into this hobby for losses! Or are you?!

How many Glofish can be kept in a 20-gallon tank?

This is just the perfect size for a group of 5-6 glofish. Here, they can literally thrive and reach an average lifespan of 3 years. Ensure you keep the right number of decorations and live plants to avoid consuming too much of the swimming space.

We highly recommend this size for a novice hobbyist. You can easily tend to your fish whilst keeping optimal water conditions. Additionally, all species – danio, tetra, tiger barb and rainbow shark – can thrive here with their tank mates.

Can GloFish live with other fish?

Can Glofish live with other fish?

Yes, they can. However, specific species of glofish are compatible with different types of fish. To understand this better, let’s have a look at some of the common species of glofish.

Glofish species

  • Glofish Danio: This is the most common type of glofish. They are small and reach a maximum length of 2.5 inches. They are very social fish and are compatible with numerous tank mates. Ensure there is enough swimming space as they like darting around and chasing tank mates.
  • Glofish Tiger Barbs: These fish are semi-aggressive and tend to be a bit full of themselves. We might even call them overconfident? They like to keep themselves in large groups and do not get along with tank mates. In fact, they are known to nip and bite them. They like a densely planted tank.
  • Glofish Tetras: These fish are peaceful and colorful schooling fish. You can even make a rainbow with them … no pun intended. They tend to get along with numerous tank mates. Unlike their brothers, glofish danio, they are laid back and don’t require much swimming space.
  • Glofish Rainbow Sharks: This semi-aggressive species is the newest addition to the glofish family. They reach a maximum length of 6 inches. They are not compatible with numerous tank mates. They are bottom-feeders that spend much of their time devouring what is on the substrate.

These are the common species of glofish that you can find in your nearest pet store. So, which are some of their tank mates? Let’s have a look for each individual type of glofish.

Glofish Tank Mates

Glofish Tank mates
Tetra Glofish Angelfish, Barb, Betta, Cichlid (observe caution), Cory Cat, Danio, Discus Fish, Tetras, Rasbora, Minnow, Molly, Guppy, Swordtail, Killifish, Hatchet
Rainbow Shark Glofish Barb, Danio, Gourami, Minnow and Rainbow Fish.

You should exercise caution with the following tank mates: Rasbora, Tetras, Sharks, Platy, Pleco, Guppy, Hatchet, Killifish, Loach, Molly Discus fish

Danio Fish Angelfish, Barb, Betta, Cory cat, Danio, Discus fish, Hatchet, Killifish, Loach, Molly, Minnow, Platy, Pleco, Rainbowfish, Rasbora, Tetras, Swordtail
Tiger Barb Glofish Barb, Cory cat, Danio, Gourami, Guppy, Loach, Molly, Minnow, Pleco, Rainbowfish, Rasbora, other sharks, Tetras

These are some of the compatible tank mates for different types of glofish. Observe caution when keeping tank mates with the rainbow shark and the tiger barb. This is because they are aggressive and tend to nip and bite other fish.

How big do glofish get?

Glofish can grow to different sizes, depending on the species. As such, it is paramount to consider their size when choosing tanks. So, how big can they get?

  • Tiger barb glofish: maximum size of 3 inches
  • Danio fish: maximum size of 2.5 inches
  • Glofish tetras: maximum size of 2.5 inches
  • Rainbow shark glofish: maximum size of 6 inches

As such, it is not advisable to keep a rainbow shark glofish in a 10-gallon tank. The ideal size is a 30+ gallon tank.

Which are the ideal water and tank conditions?

Although glofish species require different water conditions, the following conditions are the most ideal for all for all of them:

Temperature: 72-82°F. Ensure you have an aquarium water heater to keep temperatures constant and a bit on the warm side.

pH levels: 6.0-7.0

Also, ensure there is enough swimming space for danio and tiger barb glofish.

Oh, and never forget that glofish are meant to GLOW. As such, enough lighting is paramount in your tank. Blue light is preferable as it illuminates the colors of your glofish. Additionally, purchase decorations and gravel that glows under the blue light.

This way, you will keep your glofish happy whilst achieving that aesthetic touch.

Ideal tanks for Glofish

The size of the tank will depend on the glofish species. However, there are common tanks that can do well with numerous glofish, they include:

GloFish Aquarium Kit Fish Tank

Check On Amazon

This is a perfect tank for most glofish. It comes with LED lighting and you can choose numerous colors. It’s perfect for GloFish!

Aqueon NeoGlow 10 Gallon Orange LED Kit

Check On Amazon

Well, this is arguably the best tank. It comes with a blue LED lighting system. It includes florescent artificial plants and multi-colored gravel. Together with your colorful buddies, it presents an appealing aesthetic feeling to your room.

SeaClear 10-gallon mini-kit

Check On Amazon

This mini-tank is just the perfect tank to add color to a small room. It comes with all accessories required to give that aesthetic touch, apart from gravels – which you can easily find elsewhere.

It comes with an adjustable lighting system so that you can choose which light you want. It has a powerful filter, appealing plastic plants, and a net.

Which are some of the most ideal glofish tank accessories?

So you want to make your tank more appealing? Here are some Recommendations, linked to Amazon:

These and more are the perfect additions to your glofish aquarium.

Bottom line

Glofish are colorful fish buddies that you can keep at home. They are easy to look after and tend to get along with numerous tank mates. We recommend keeping them in a 20-gallon tank or bigger, especially for rainbow shark and tiger barb.

Always remember that glofish are genetically modified with fluorescent genes and are mostly bred in captivity. So, which species intrigues you the most? Let us know!

Related Questions

Can a glofish live alone? No, a glofish is not supposed to live alone. They are naturally schooling fish that need to live in groups of 5-6 fish. Additionally, they are compatible with numerous other fish.

What happens if I overcrowd my tank? It can lead to aggression and poor health. Some fish can die of hunger due to stiff competition from tank mates. Avoid overcrowding a tank for optimal health and color glow.

Ines Walp

Wednesday 16th of September 2020

I agree with you

Terri Delahoussaye

Thursday 6th of August 2020

how many glofish should I put in a new aquarium?

Jackie A Ellis

Saturday 1st of February 2020

Hi enjoyed reading your information ???? I have a question how often should I do a water change out and how do I clean up the gravel in the bottom of the tank? Thank you

Saurabh Kumar

Saturday 1st of February 2020

Hey Jackie thanks for sharing your feedback! You can Replace ten to fifteen percent of aquarium water every week to keep nutrients low. You can use something like a Gravel Vacuum to clean the bottom of the tank. You can check this one on Amazon!

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