How Many Glofish in a 10 Gallon Tank? (Essential Advice)

Glofish genetically engineered fluorescent fish

Unlike anything else in the world of fish in aquariums is the Glofish! They are magnificently colored, spectacular fish which have had a natural fluorescence gene added to their genome, resulting in fish that are permanently fluorescent. In this article we delve into the question: How Many Glofish in a 10 Gallon Tank?

We also look at how glofish were developed and the care requirements for the different glofish species.


Introducing the Glofish

How Many Glofish in a 10 Gallon Tank

Due to bright neon colors, these fish have become extremely popular amongst beginner fish-keepers.

Genetically modified glofish are born with brilliant color, maintain it throughout their lives, then pass the color to their offspring.

Glofish have the same general care requirement, including temperature and food preferences as their non-fluorescent counterparts.

They are great in a community aquarium! The best way to experience glofish is by using blue lighting. This is included in all branded Glofish aquarium kits to help everyone ‘take home the glow!’

Glofish have been developed from several species of aquarium fish. Later in the article we consider each of these species and their individual care needs.

Glofish History- How Did They Come About?

Back in 1999 a group of scientists in Singapore were working with a gene extracted from a jellyfish that produced a bright green, fluorescent coloration. They then inserted this gene into a Zebra Danio embryo, allowing it to integrate into the fish’s genome.

These fish would then be fluorescent green under white light or ultraviolet lights. They then filed a patient on their work.

Next, they created a red florescent Zebra Damio using genes from a sea coral. The scientists then met with businessmen from Yorktown Technologies and created a deal to have world wide rites to market the new Zebra Danios branded as Glofish.

Are Glofish as Hardy as the Fish They Were Developed From?

So essentially Glofish are genetically modified, or GMO fish. Since then, there have been several new forms of glofish using other tropical fish species.

The glofish available on the market now include the Zebra Danio, Tiger Barb, Rainbow Shark, White Skirt Tetra, and Betta Fish.

The fish that glofish were developed from were all considered to be hardier- more ‘forgiving’ fish when mistakes are made with water parameters. Unfortunately, these new varieties don’t seem to be quite as hardy as their new counterparts.

So, is it that they are less hardy, or is it because they have been kept in inappropriate environments?


How Many Glofish in a 10 Gallon Tank? Things to Consider.

Types of Glofish and their colors

There is a lot of good to be said about glofish because of the bright colors. These fish are very attractive to a younger audience. They can add a great bit of color to a community aquarium.

The worst thing about glofish, is not the fish themselves, but more the tanks that are marketed for the fish.

For example; the largest aquarium kit marketed for glowfish is 10 gallons, whilst most of the species that glofish have been developed from require a minimum of a 20 to 30 gallon tank for optimal fish health.

So, you can see how this might be confusing to a lot of fishkeepers!

Another issue with these fish is that they were genetically modified to have bright lighting bring out their florescent colors. The species used to develop the glofish become stressed if kept in brightly lit tanks. As with White Tipped Tetras and Betta fish being examples of this.

The glofish are really not the problem, the problem is how they are marketed and how the products for them are marketed.

Co-inhabitants and Fish Behaviors that Determine Tank Size

Glofish cannot just be added to any community aquarium expecting that all aquatic life in the tank will be happy. Some glofish species like Tiger Barbs and Bettas tend not to get along well with others without careful planning and sufficient space in the tank.

Tiger Barb glowfish cannot be mixed with Betta fish glofish. Tiger Barbs are well known fin nippers. They will also outcompete the bettas for food.

Tiger Barb glofish are better kept in larger groups of ten fish. This reduces their nipping tendencies.

The rule of thumb of 1 gallon of water per Tiger Barb, definitely doesn’t work when considering a 10-gallon tank!

A 10-gallon tank is way too small for 10 Tiger Barbs. At the very least you would need a 20-gallon tank. Really, 30 gallons or more is better.


Wrong Advice from the Glofish Website

The glofish website does not have really good information on how to care for their florescent fish properly.

For example: the official glofish website recommends a tank of 10 gallons for a group of 6 Betta female fish. A 10-gallon tank will not be adequate for six female bettas. You would want at least a 20-gallon tank. Bigger always means better!

The truth is, while some people may object to glofish being sold on the market, as long as they keep selling, they will keep coming out with new species of glofish.

The best thing we can do is to research the specific species they were developed from and try to educate ourselves on how to best take care of them.

Focus a little less on what will best show off the bright colors of the fish, but more on the fish’s needs for it to thrive in your tank.


How Many Glofish in a 10 gallon tank? Shape Does Matter

If you do decide to house your glofish in a 10-gallon tank, then considering the shape of the tank will help your fish with finding the space to move as it would do naturally.

Tall thin tanks are less suitable. Tetras, tiger barbs and danios are schooling fish and need space to move left to right. Housing them in a longer tank is better.

The same goes for betta fish. These fish originated from shallow waters where they swim from side to side.


Glofish Species and Their Specific Needs

Zebra Danio Glow Fish

Long Finned Zebra Danio Glofish

Being the original glofish, they have developed several color strains. Today they are available in five colors: Electric Blue, Star Fire Red, Sun Burst Orange, Cosmic Blue, and Galactic Purple.

Danios require at least a 10 gallon tank. They are fast ‘busy’ fish suited for busy aquariums. They like to swim in the upper portions of the tank.

Danios are schooling fish, so they need to be kept in groups of at least five. If the numbers are too low they become stressed, which can lead to illness and social problems in the aquarium.

These colorful fish need plenty of space to swim around. They cohabitate with Tiger Barb glofish and White Skirt Tetra glofish, so long as they have room in the tank.

Your aquarium would need a lid, as danios like to jump. A filter or aquarium water pump that creates a current will excite danios. They like to dance around in the current.

Water Parameters:
  • Temperature: 65° – 75°F
  • pH: 6.5 – 7.2
  • Water hardness: 3 – 8 dkH (soft to medium)


Tiger Barb Glofish

Electric Green Glofish Tiger Barb

The glofish version of the tiger barb comes as a florescent green called the Electric Green Tiger Barb.

Tiger Barbs require a minimum tank size of 20 gallons (30+ gallons is better). Being avid swimmers, they need space to race around the tank pursuing each other.

Tiger Barbs grow to three inches if provided with the right conditions. So, having 6 to 10 barbs in a ten gallon tank would make it way to crowded. A larger tank will lessen any aggressive behaviors.

Water Parameters:
  • Temperature- 68° – 82°F (74° F best)
  • pH range- 6.0 – 8.0 (slightly acidic is best)
  • Water hardness- 4 – 10 dkH


White Skirt Tetra Glofish

Electric Blue White Skirt Tetra Glofish

There have been three glofish color versions developed from the White Skirt Tetra. These are: Electric Green, Sunburst Orange, and Moon Rise Pink.

This species is a schooling fish, with fish growing to two inches long. Schooling fish, because they need to be in numbers, require a large tank of at least 20 gallons (114L).

It is best to keep them in groups of five or more in a community tank, otherwise they are susceptible to getting their fins nipped.

Water Parameters:
  • Temperature: 75° – 80°F
  • pH range: 6.0 – 7.5
  • Water hardness: 5 – 20dkH


Rainbow Shark Glofish

Sometimes known as the Red Finned or Ruby Shark, are a semi-aggressive fish towards other species with long fins such as guppies, bettas and goldfish.

An adult rainbow shark thrives in a tank with a minimum of 55 gallons of water and an aquarium length of 48 inches. This species grows to six inches (15 cm) long and require room to move. A 10 gallon tank would not suffice.

Rainbow Sharks are bottom to mid-level tank occupants who will get along with Tiger Barb glofish.

The Glofish brand has developed a purple/pink florescent Rainbow Shark which is names Galactic Purple.

Water Parameters:
  • Temperature: 75 – 81 °F (24 – 27 °C)
  • pH range: 6 – 8
  • Water hardness: 5 – 11dkH


Betta Fish Glofish

Male Betta Fish Glofish

The betta glofish cause quite the controversy in the fish-keeping community. The glofish brand developed the Electric Green Betta with a florescent green color. The basis of the controversy is that the betta fish is already a stunningly colorful fish which is super popular with fish enthusiasts. The glofish betta doesn’t match up to the range of patterns and colors of bettas that have been selectively bred for many years.

The other problem with the glofish betta is that it doesn’t have the desired fins.

As pointed out earlier, the glofish website recommends six female glofish bettas for their 10-gallon tank. Our view is that one betta fish requires a minimum of 5 gallons or larger for it to have space to move and for water parameters to keep stable.

Betta fish are not social fish and need room between individuals. Females will tolerate one another, but will become stressed if crowded together. When this happens social problems occur and fins may be nipped.

Water Parameters:
  • Temperature: 75 – 81°F (23.8 – 27.2°C)
  • pH range: 6.5 – 7.5
  • Water hardness: 3 – 5 dkH
  • GH: 3 – 4 dGH


Final Thoughts

Whether you have an aversion to GMO developed organisms or not, the glofish are now well established with the aquarium hobby and we all agree that the colors that have been developed are unique and eye catching, especially in an aquarium with ultraviolet lighting!

Our responsibility with keeping pets is to ensure they are kept in appropriate tanks where their needs can be met that replicate their natural habitats. ‘How Many Glofish in a 10 Gallon Tank’ is not the question that should be asked, but rather; What size tank would be suited best for the species of fish intended to be kept? This goes for aquarium equipment as well- lighting systems, filters and heaters.

Whatever you decide, we wish you every success with keeping glofish.

You may be interested in our article “How Many Glofish in a 5-gallon Tank?” It is quite a different article to this one.







How Many Glofish in a 5-gallon Tank? The Ideal Tank & Mates!

How many glofish in a 5-gallon tank

It’s no surprise that the colorful Glofish catches your eye! Many new aquarium enthusiasts are drawn to the fish that could potentially become a new addition to their aquarium. Not just the fluorescent colors that make these fish attractive, but the minimum care they require makes them perfect for beginner aquarists. This article will help you determine how many glofish in a 5-gallon tank that you can keep.

We will also look at the requirements for caring for glofish, tankmates and the different types of glofish available in pet fish stores.

What is a Glofish?

How many glofish in a 5-gallon tank

Glofish don’t occur in nature. They are a genetically modified (GMO) fish .

Singaporean scientists found a way to take a florescent green gene from a jelly fish and introduce it to the genome of an embryo of a Zebra Danio fish, creating a glowing green fish.

Having success with developing a unique fish that glows green, the scientists then found other bright colored genes from other creatures, such as a red coral, and following the same procedure managed to develop other danio fish colors.

Today, these little guys come in a variety of florescent colors to include; green, blue, red, yellow, purple, and pink.

Not only have they developed these colors for the Glofish Zebra Danio, but they have been successful in creating awesome colors for other aquarium fish species.

The popularity of these fish has grown more and more, especially with people who want killer displays where they use blue ultraviolet lights to bring out the glow!

The most common glofish species are Glofish Tiger Barbs, Glofish Rainbow Sharks, Glofish White Skirt Tetras, and Glofish Zebra Danios.


How many glofish are recommended per gallon of water?

That ‘inch per gallon’ rule was not, and will never be true regarding all types of fish. Imagine having a 10 inch fish in a 10-gallon tank!

It is important to use common sense when populating your aquarium. Every fish species is different and has different requirements and glofish are not any one specific species. Many considerations need to be thought about when setting up a tank that will include glofish such as:

  • Schooling fish needing the comfort of a group of fish to be content.
  • Fast swimming fish requiring wide-open areas to swim.
  • Aggressive or territorial fish who cannot be to close to one another.
  • The size the adult fish will grow to.
  • Water parameters may differ between different species in the tank.
  • Compatible tankmates.

How Many Glofish in a 5 Gallon Tank? Let’s Consider Each Glofish Species

How many Danio GloFish in a 5-gallon tank?

Danios grow to 2.5 inches. With the 1 inch per gallon rule, you would only have two danios. The problem with that is,

Glofish Danios are very active, social schooling fish.

They need to live in a school with more than just one other individual, and they need space to dance around the tank.

Zebra Danios like to occupy the surface areas of the tank, with a tendency to jump. A lid is essential with this species.

Danios like a flow or current in the water, that replicates the streams of their natural habitat. Using your filter pump to generate a current will suit them well.

Keeping danios with say a glofish betta would not work. For one, the betta does not handle currents and bettas become stressed when they don’t have space to move.

Although Glofish Danios are hardy and can tolerate substandard water quality, they do require warm water between 65 to 75 degrees Fahrenheit. So an aquarium heater is essential. Ideally, give them a pH between 6.5 – 7.2 and water hardness between 3 – 8 dkH.

A 5 gallon tank really is far too small for a school or Glofish Danios. You will be fraught with problems keeping the water healthy and the fish will become stressed without having space to move. This will only lead to disappointment.

Having only two danios in the 5-gallon tank would not look impressive, as the aim with keeping glofish is to see them displayed in a school flashing multi-colors as they swim about.

Our recommendation would be a 20-gallon tank with a school of 6 to 10 Glofish Danios. This would look awesome and the fish will do so much better.

How many Glofish in a 5-gallon tank? The Rainbow Shark Glofish

Even a 10-gallon tank is not enough for one Rainbow Shark. At the very least you would require a 30-gallon tank.

Rainbow sharks grow quite large (6 inches long) and are aggressive towards the timider fish. They cannot be kept in confined spaces. Rainbow sharks are best kept with other fish that can match their traits. Glofish Tiber Barbs would be a great match for Rainbow Sharks.

Sharks are bottom feeders, and they do a great job fossicking around rocks, substrate and plants keeping the tank clean. Rainbow sharks require caves and places to hide away. They are a hardy species of fish and will tolerate water that is not at its best.

Rainbow sharks enjoy a temperature between 75 and 81 degrees Fahrenheit, with a pH range of 6-8 and water hardness 5-11 dkH.

We recommend a 40-gallon tank for one fully grown Rainbow Shark. The tank would need to be long, rather than tall, as these fish like to swim left to right scavenging the substrate, not up and down.

How many GloFish Tiger Barbs in a 5-gallon tank?

Electric Green Glofish Tiger Barb

Tiger Barbs are semi-aggressive schooling fish. They are not fussy when it comes to water parameters. A temperature between 68 and 82 degrees Fahrenheit, pH range of 6 – 8 and water harness between 4 – 10 dkH.

A 5-gallon tank will not suffice for Tiger Barbs. A school of six would require at least a 20-gallon tank. These fish grow in no time and will reach three inches long, filling the tank space quickly.

Tiger Barbs are fast swimming fish often seen chasing each other around the tank. Without space they will develop social problems.

If housed in a 30+ gallon tank, you would be able to incorporate tank mates with a small school of Tiger Barbs. Choose tank mates that can match their vigorous behaviours, not timid fish with long fins. Tiger Barbs will not be able to resist nipping them!

Glofish Tiger Barbs would look impressive darting around in a school. Just ensure the tank is large enough!

How many GloFish Tetras in a 5-gallon tank?

How Many Glofish in a 5 Gallon Tank Tetras

Unlike the Tiger Barbs, GloFish White Skirt Tetras, are peaceful fish that grow to 2.5 inches long. They live in schools and for them to be happy in your aquarium a school of at least five or six fish would be best.

These tetras are very hardy fish and can tolerate water conditions that may not be optimal. A temperature range between 75 to 80 degree Fahrenheit, pH 6 – 7.5, and water hardness range of 5 – 20 dkH.

They can be shy, so add some plants to the aquarium to provide them with plenty of places to hide and rest. Ensure space for them to swim around in their school.

The tetra glofish is a great beginner fish and in our view would be the easiest to keep out of all the glofish species.

A 5-gallon tank would not be suitable for this schooling species. A minimum of 20-gallons would accommodate a small school of tetras on their own.

How Many GloFish in a 5-Gallon Tank? The Betta Fish Glofish

You would be able to keep one male betta in a 5-gallon tank or two female bettas.

Betta fish are aggressive towards each other, especially males. They don’t cope well in confined spaces with other fish.

Bettas are very forgiving when it comes to water parameters. They have a labyrinth organ on top of their head that allows them to breath air from the water surface if there is a lack of oxygen in the water. Having said this, they do require care, and having a good tank filter and a heater will ensure they enjoy a longer healthier life.

Glofish Betta Fish prefer a water temperature between 75 – 81 degrees Fahrenheit, pH range of 6.5 – 7.5 and a water hardness range of 3 – 5 dkH.

Bettas like places to hide away, so plants and ornaments make great additions to the tank. Their long fins inhibit movement when there is too much water flow in the tank. Water flow through filters will need to be adjusted down or locate the filter behind an ornament in the tank.

Betta fish don’t do well with more aggressive fish such as Tiger Barbs and Rainbow Sharks. These guys may end up nipping the fins of the betta fish.

Bettas can cohabitate a community aquarium, so long as there is enough room for them and plenty of places to hide away if they need to.


Related Questions

Zebra Danio Glofish

Are glofish schooling fish?

Some Glofish species are naturally schooling fish. They are social fish, feeling secure when swimming with a group of others. Tiger Barbs, Zebra Danios and White Skirt Tetras are all schooling fish.

When these fish don’t have a group of companions, social problems set in. Fish may become aggressive or nip fins. This is especially the case with Tiger Barbs. A 5-gallon tank will not suffice for schooling fish.

Can Glofish live with other fish?

The compatibility of the fish with other aquatic creatures will depend on the species of GloFish in question. For

example, bettas and barbs can be aggressive with one other and towards other less dominant species in the tank.

On the other hand, danios and say rainbow sharks in the same tank would work well as they occupy different areas of the tank- danios at the top and sharks in the lower areas.

There are many compatible aquarium fish that can coexist with the different species of glofish.

Careful planning and educating yourself on the needs of each fish species will save you heartache. Many new fish-keepers tend to overstock their tanks with incompatible species.

These people then have water quality challenges to keep abreast of, and social problems in the tank, all resulting in the likelihood of fish dying.

A 5-gallon tank is not suitable for a community aquarium, it is way too small. In our view 20-gallons is the very minimum.

What do you feed glofish?

The best food for all the glofish species is a high-quality tropical fish food. Some people choose to add live and frozen foods to add variety to their fish’s diet.

Keep in mind that the different glofish species occupy, and therefore feed, in different parts of the aquarium. For example, Danios would do better with a floating flake, whilst Rainbow Sharks with sinking granules.

Glofish bettas are slow to get to the food and will be outdone by aggressive feeders such as Tiger Barbs.

How long do glofish live for?

The average life of Glofish is between 3 and 5 years. This will vary between the different species. Sharks grow to six inches and may live longer than the smaller species.GloFish Aquarium Sand 5 Pounds, Black with Highlights, Complements Tanks and Décor, (AQ-78485)

Ultimately, for long living fish it will all come down to how well they are cared for. A large tank, with a quality biological filter, aquarium heater and regular water checks; together with good food and space in the tank for fish to have room to swim and establish territories will increase the lifespan of glofish.

What size tank do glofish need?

There is no tank or system exclusive to Glofish. They are different fish species with different requirements.

However, in general all the glofish species are quite hardy tropical aquarium fish and can be given the same care as other tropical fish would get in a mixed community aquarium.

If keeping only one species of glofish a tank of at least 20-gallons is recommended for all schooling species.4 Pieces Silicone Glow Fish Tank Decorations Plants with Simulation Silicone Coral, Artificial Horn Coral,Fluorescence Sea Anemone for Aquarium Fish Tank Glow Ornament That way you could keep 6-10 in a school.

If mixing them up with other aquarium fish, then we recommend a minimum of 30-gallons. With a tank this size you would be able to accommodate ten to twenty smaller fish of mixed species.

Keeping Rainbow Shark Glofish will require a 30-gallon tank to cater for them when they reach adult size (6 inches). Being semi-aggressive fish, they require space.

The only fish that could inhabit a 5-gallon tank would be a single betta fish or perhaps two female bettas.

In our view, bigger aquariums are always better. Much easier to keep the water optimal for fish, less fish disease and they require less maintenance.

Do glofish require special lighting to make them glow?

The short answer is yes. The colors are emphasised when ultraviolet lights are used in the tank.GloFish Treasure Chest Ornament, Small, Detailed Aquarium Ornament, Hideaway For Fish

The Glofish brand sell aquarium kits that include the ultraviolet lights. The tanks look impressive when turned on at night bringing out the glow.

The problem with the tanks they market is that they are too small for the number of fish they recommend. Their 5-gallon tank kit would only be suitable for a single betta fish. Their 10-gallon tanks could take four or five glofish tetras.

They are yet to sell a 20-gallon aquarium kit which, in our view, is the minimum size for glofish.

The ultraviolet blue lights do create a stunning display; however, they are not healthy for any species of fish. In the natural environment, fish are exposed to a full spectrum of light coming from the sun.

Having only ultraviolet lights will stress the fish leading to health problems and a shortened life span.

Our suggestion would be to have a lighting system that gives full spectrum light but can also switch to ultraviolet blue or white light. That way your fish and plants get the appropriate lighting, and when you want to show off your glofish you can switch the lights over to bring out the glow!

What tank accessories do I need for a glofish aquarium?

The most impressive tanks housing glofish have a dark background with a black substrate. This best brings out the florescent colors of the fish.GloFish LED Light 20 Gallons, Blue and White LED Lights, for Aquariums Up to 20 Gallons

There are many ornaments and aquarium decorative accessories that also glow when ultraviolet lights are used. These help to create a colorful wonderland.

Always use a correctly sized filter and a heater to maintain temperature and water quality.

What plants should I have in a glofish tank?

A planted aquarium requires a spectrum of light that will help them grow and look their best. If only using ultraviolet lighting plants will not survive. You would be better off using artificial plants.

Glofish species, like other aquarium fish, enjoy a planted aquarium. It offers hiding places, better water quality and provides a source of food. Java Ferns and Anubia plants are always a good call.

What pH do glofish require?

Glofish are relatively robust fish that will thrive in different pH levels; read our guidelines about individual species to see what is their ideal pH.

Which glofish give the best effect in a glow-tank?

The schooling species of glofish look great amassed in an aquarium. Especially, long finned danios that dance around flashing their colorful flowing fins.

Schooling tetras and Tiger Barbs also look awesome!

Danios swim around the surface and tetras in the mid water, so combining these two species would fill the aquarium from top to bottom.

To amass a school for greatest display, a large tank is required.

In our view, the glofish betta is not as impressive as the brilliantly colored betta fish that have been selective bread for finnage and color for decades. The glofish betta lacks the finnage of its counterparts.


Final Thoughts

Glofish are genetically altered fish with fluorescent genes that have been bred in captivity. Depending on the species, they are easy to take care of and tend to get along with numerous tankmates.

The size of the aquarium depends on the species of Glofish and how many to be kept. Try always to use large tanks. Our topic with this article for this artic was to answer the question: ‘how many glofish in a 5-gallon tank?’ Although a 5-gallon glow tank, as marketed by the Glofish company, would look amazing, it really is not a suitable option!

If interested read our article ‘How many glofish in a 10-gallon tank?