How To Care For Glofish? The Ultimate Guide

People have been actively raising various kinds of fish in the aquarium for many years. The enthusiasm and knowledge towards aquarium hobby are increasing gradually as more information is available thanks to the internet. There are numerous types of fish on the market and you have to take into account several factors before choosing one.

In this article, we would like to talk about Glofish. It is a genetically modified fluorescent fish originating from four different fish such as zebrafish, tetra fish, barbs, and rainbow sharks. There are dozens of reasons why people get attracted to this fish but most importantly it is extremely easy to look after.

Are Glofish Easy To Take Care Of?

Yes, it is often recommended to beginners who are new to the aquarium hobby and they are energetically trying to acquire knowledge and useful skills to raise Glofish successfully.

There is indeed a lot to know regarding the living conditions of this fish and it might end up with tragic results if you are not aware of them. We are willing to provide the ultimate guide and teach you how to take proper care of Glofish. It is truly a magnificent species and you will enjoy living with Glofish tremendously.

Do You Know How Glofish Were Created?

First of all, we want to describe the history of Glofish and the main reasons why this fish was developed in the first place. It is a first-ever genetically engineered fish deriving from the original zebra fish also known as zebra danio. 

 Zebra fish is located mainly in the rivers of Bangladesh and India as they are tropical fish which makes it impossible for them to survive the climate of North America. Scientists at the National University of Singapore were working with fluorescent protein genes produced by a jellyfish. They are able to create a natural green fluorescence and scientists have transferred this ability into zebra fish by inserting the fluorescent gene into its embryo. 

Glofish - the ultimate guide-1
Glofish – the ultimate guide

 As a result, zebra fish was able to brightly fluoresce in the presence of ultraviolet light as well as natural white light. The name Glofish represents this attribute as it became the first and only fish capable of glowing under certain lighting conditions. 

What Is The Purpose Of Glofish?

 The initial goal of modifying zebra fish was to detect the toxins in the water and discover the polluted waterways. Glofish was supposed to glow in the company of these toxins which would help people identify contaminated areas and protect the local communities using these waterways. 

 Shortly after creating the first genetically modified fish, scientists at the University of Singapore followed up by developing a line of red and orange-yellow fluorescent zebra fish. For the red fish they used a gene from sea coral and different variants of jellyfish genes were added to make an orange-yellow zebra fish. 

 Nowadays, we can see 12 species of Glofish containing various colors. The first-ever aquarium fish was bred in 2003 by Yorktown technologies and it was called a Starfire Red Danio. Later that year, Glofish was introduced to the USA market after a long time of research by the Food and Drug Administration. 

Glofish - The complete Guide-1
Glofish – The complete Guide

 In the next part of this article, we are going to cover every necessary topic related to the proper care of Glofish. Continue reading to find out everything you need to raise your Glofish successfully and make a comfortable living environment for it.

Glofish Feeding

It is extremely important to know how to feed your Glofish properly and get familiar with their diet. This is one of the most essential topics regarding every domesticated individual and Glofish is not an exception as well. It requires a healthy diet containing different kinds of nutrients.

Are Glofish Omnivores?

We would like to highlight that Glofish is omnivorous species meaning that it is capable of consuming both plants and animal matter.

Glofish Ultimate Guide-1
Glofish Ultimate Guide

Due to the fact that it is a genetically modified fish, the majority of people think they eat something different and unusual. This is a false viewpoint and you should remember that Glofish is no different than their natural counterparts when it comes to the feeding diet. It is the same for both individuals.

What Kind Of Food Do Glofish Eat?

Generally, it is recommended to feed your Glofish with both frozen and live food. They don’t require a high amount of protein as they are omnivorous fish and simple protein provided in live food should be sufficient for them.

As for the benefits of frozen food, we can emphasize that it will decrease the risk of developing different kinds of diseases and parasitic infections. Therefore, it is necessary to make frozen food part of daily feeding and it must become a staple food for your Glofish.

We have made a list of the most suitable food for Glofish and they contain every necessary nutrient to keep them healthy. The list includes –

  • Bloodworms – They are considered to be one of the best meals for Glofish. Bloodworms give your fish extra energy and we recommend going for Omega One Freeze-Dried bloodworms as they are rich in protein and minerals.
  • Brine Shrimp – It is one of the most popular live foods for aquarium fish and also a very good option for your Glofish. They provide a big amount of vitamin A and vitamin D and the protein capacity is high as well. Like the bloodworms, our suggestion would be to purchase Omega One product for this one as well.
  • Flake Food is responsible for promoting the brilliant colors of this fluorescent fish. There are various kinds of flake foods containing different proteins and ensuring healthy life you Glofish. You can see them on the official website of Glofish.
  • Frozen Food – As we have mentioned above, frozen food is important for any fish as they help to reduce some infections and illnesses. You need to make sure to provide your Glofish as much freeze-dried food as possible and it will be good if you thaw them first. This way, you will significantly decrease the risk of different diseases.
  • Pellets – They are also an important part of Glofish’s diet. Pellets are a good way to enhance the colors of your fish with the help of beta carotenes in salmon skin and we advise you to go for Omena One Color Mini Pellet for the best quality.

These are the main dishes for your Glofish and you can also use different types of veggies and meaty foods for your diet. There are dozens of special flakes available on the market and they include every essential nutrient intended to strengthen the health of your fish.

We want to highlight that Glofish does not require any type of special food. The feeding requirements of Glofish are exactly the same as their non-fluorescent counterparts and you can easily maintain the balance of their diet if you utilize the above-mentioned food.

How Many Times A Day Do You Feed Your Glofish?

The most important thing to remember is that you should never overfeed any kind of aquarium fish including your Glofish.

Flake Food - Glofish
Flake Food For Glofish

Our recommendation is to feed the Glofish twice a day and make sure to consume food within two minutes.

Additionally, you should control the feeding process well in order to provide meals for every individual inside the aquarium. They are constantly fighting and stealing each other’s food.

As long as you won’t overfeed Glofish and maintain the right balance of diet your aquarium will have healthy residents!

Glofish Aquarium

There are several factors to take into consideration when it comes to the aquarium of Glofish. We have already noted that beginner hobbyists find this fish suitable as they do not require too much effort to look after. However, there are still some works to be done regarding the tank in order to experience your Glofish in the best way. 

Can You Have One Glofish?

Glofish is community fish and they need several companions in the aquarium. Our suggestion would be to get approximately 10 Glofish in order to make life comfortable for them. 

Glofish Complete Guide
Glofish – Complete Guide

How Many Glofish Can Live In a 20-Gallon Tank?

If you are willing to rear 10 Glofish in your aquarium then you should get at least a 20-gallon tank.

However, the general recommendation is that you should always go for the largest option when it comes to the tank of Glofish. There are several reasons behind it, first of all, some types of Glofish are relatively longer and they require more space. Secondly, when you have a broad area in the tank you are able to insert some bottom eaters to clean up the leftover food. 

You have two choices when it comes to the substrate of the aquarium. Glofish is able to live with the sand as well as gravel and it is up to you to decide. Each of them has its own advantages – the sand is good for accumulating waste on the top where it’s easy to remove and the gravel helps to reduce the pollution in your aquarium.

What Kind Of Lighting Do Glofish Need?

It is also very important to decorate the tank. First of all, we want to talk about lightings as they are what makes Glofish fluoresce.

It is a unique ability of this fish to glow and you are able to witness it only when you install black or blue LED light fixtures to your aquarium.

It is a good way to start decorating your aquarium and along with the dark environment, you will see this beautiful picture. 

Additionally, you have the possibility to add different plants or rockwork decorations to make your tank look delightful. In this case, you will need broad-spectrum lighting to provide energy for them and to brighten your aquarium. 

Do Glofish Have To Have A Filter?

You should not forget that it is essential for the health of Glowish to use a filter. It reduces the risk of developing different contaminants such as nitrates and ammonia and they can be deadly for your fish.

Glofish in Aquariums
Glofish in Aquarium

You have several options but generally, a sponge filter is convenient for small tanks whereas you can use Aqua Clear Power Filter for larger aquariums. 

Do Glofish Need A Heater?

As for the aquarium temperature, they love to reside in a hot environment because they are tropical fish. So, generally, it is a good idea to have your tank temperature between 72 and 80 Fahrenheit.

It is a good idea to add a heater to your aquarium to keep your fish healthy and energetic. You should choose a proper heater depending on the species you have and we will give you a basic idea for every type of Glofish. 

  • Glofish Rainbow Sharks come from very hot environments and in order to mimic their natural habitat you should add a 150–250-watt heater in the tank with a temperature of 72-79 F.
  • Glofish Tetras come from the warm waters of South America and they also require a heater to match the temperature of their natural environment. If you have a 10-gallon tank you will need a 50-watt heater and a 100-watt heater is sufficient for the 20-gallon tank.
  • Glofish Tiger Barb resides mainly in the warm rivers of Indonesia and Borneo. They also need a heater to stay healthy and the recommended temperature would be 74-79 F. As for the heater, 150-watt should be enough for a 30-gallon tank.
  • Glofish Danio is the only species that can endure a cold environment and you don’t necessarily need a heater for them. They are able to live in an unheated aquarium with a water temperature of 64-75 Fahrenheit. 

You will need to learn proper techniques to set up these appliances correctly. They require simple steps and you will acquire them easily. Also, your Glofish might take some time before it gets familiar with the new home when you transfer it to the tank. You should look for the signs of aggression and optimize everything in your aquarium to make life comfortable for Glofish. 

Glofish Breeding

We want to start this guide by informing you regarding the breeding of these creatures. It is very important to have a thorough knowledge of this topic in order to maintain inhabitants in the aquarium.

What Happens If You Breed Glofish?

The majority of people have misconceptions about this genetically modified fish especially when it comes to breeding as some of them think that colors of Glofish are dyed or injected.

Interestingly, the ability to glow will be handed down to offspring when you breed Glofish and every new generation will keep its beautiful color.

Glofish is patent protected which means that there are some restrictions regarding its breeding. It is prohibited to sell or give away your Glofish when you breed them. Additionally, you should have enough resources to take care of them because you are not allowed to liberate Glofish into the wild. It can have a dangerous outcome and if you look after them carefully your aquarium will have a high number of fish every spawning season.

Although the genetically modified Glofish and their natural counterparts differ in appearance, their egg-laying routines are the same. For example, Glofish danios are able to lay eggs every few days and male fish is responsible to fertilize them. 

You need to make sure your aquarium has proper conditions for them to breed and when danios lay their eggs, they will most likely be fertilized by more than one male as they like to breed in groups. 

You should have a separate breeding aquarium and keep male and female danios apart approximately for two weeks before putting them into it. This is because their eggs might become a feast for adult fish. 

It is extremely important to feed your Glofish properly before breeding and we recommend providing them live food such as bloodworms, food and frozen flakes, mosquito larvae, and so on.

Glofish Babies
Glofish Fries

Usually, when you introduce male and female Glofish in the tank they will start the process within 48 hours and you need to pay attention to them. If you don’t prearrange suitable conditions for fish there is a big chance that they won’t breed at all. In this instance, you have to separate them for one more week and organize your aquarium properly. 

As you can see it is not too difficult to breed your Glofsih. You just need to pay close attention to several factors such as feeding, aquarium conditions, and the overall process. As a result, you will get a healthy new generation with original colors that will make your tank delightful.

6 Best Glofish Tankmates

It is very important to choose the right tankmates for your Glofish and the best way to do it is to place them with their natural counterparts. Generally, they are pretty peaceful species and they don’t cause any damage to other fish, although barbs and danios tend to nip tails sometimes.

However, there are certain types of species compatible with Glofish and you can’t contain them with every fish. We would like to list the species that can comfortably live with your Glofish –

  • Zebra Danios – They are compatible with every type of Glofish and they will make absolutely beautiful companions with their striped black and white zebra patterns.
  • Angel Fish – It is one of the most popular freshwater fish as they stand out with their unique colors, shape, and behavior. Although they will happily live with Glofish danios and tetras, you should refrain from placing them with sharks and barbs.
  • Betta Fish – This fish is famous for its territorial requirements and they will not live with most species. However, they have been comfortable with Glofish tetras and danios and you are able to locate them together.
  • Barbs – They are most commonly kept in groups and it is characterized with durability and various colors. The whole family of barbs is compatible with every type of Glofish.
  • Rainbowfish – This species is also able to live comfortably with all Glofish. They are small and colorful freshwater fish and enjoy a tropical environment just like Glofish. So, they do well together.
  • Tetras – It will be best if you keep more than five tetras in the aquarium and you should add some plants alongside moderate lighting. They get along well with every type of Glofish in a peaceful environment but pay attention when they are with glo sharks.

As you can see you have a wide choice when it comes to the tankmates for your Glofish. Usually, they don’t show any sign of aggression and they get along very well with the above-mentioned species, so feel free to place them together.

Glofish Diseases

Generally, Glofish is considered to be an extremely durable and hardy species. However, if you don’t take good care of these fish, they might be vulnerable to some diseases. There are all sorts of illnesses and infections characterizing almost every type of aquarium fish and they are induced by several reasons. 

What Are Common Glofish Diseases?

First of all, as we have noted early, it is extremely important to feed your Glofish properly. Like every living creature, an incorrect and unhealthy diet is harmful to fish. If you take into account the above-mentioned information regarding feeding you will reduce the risk of developing different diseases that can be fatal oftentimes. 

Secondly, you have to control the aquarium conditions all the time and equip it with different features. It is a good idea to change the water every once in a while, in order to prevent some poisonous infections such as nitrates and ammonia. We would like to describe some of the most common diseases among Glofish and give you an idea of how to stop them. 

  • Velvet Disease – also known as Rust, is a very dangerous disease capable of killing every individual in the aquarium. It is caused by the species called Oödinium especially when you don’t look after your tank properly. Your Glofish will develop lethargic behavior and the weight loss will be noticeable along with aggravated breathing when they are meet this illness. Although there are some possibilities to treat velvet disease, it is not 100% promising and you should take action to prevent it in the first place. You can do it by changing the aquarium water constantly and controlling the temperature of it.
  • Mycobacteriosis – This is a chronic and, in most cases, incurable disease of fish and reptiles, and the majority of people are not aware of it shows no clear symptoms. It weakens a fish’s immune system to the point that it becomes vulnerable to other diseases and often ends up with fatal results. The aquarium fish including your Glofish becomes the prey of this disease when you add a fish with mycobacteriosis and it is very hard to cure this illness. Therefore, you have to make sure every species of newcomer fish is healthy and not carrying any type of disease.
  • Intestinal Capillariasis – It is a zoonotic disease induced by Capillaria Philippinensis and it affects fish in a complicated way. It is produced by a tiny worm by depositing eggs and when they are embryonated they are eaten by small freshwater fish. The disease can be transferred to humans when they eat infected fish raw. This way, your Glofish might get infected as well and it will show different kinds of symptoms. You should be aware of them and treat this disease quickly otherwise it may end up deadly for your Glofish.

These are the most common diseases characterizing Glofish. We would like to repeat again that it is extremely important to maintain the right balance of diet, create proper aquarium conditions, and control the relationship with its tankmates carefully. By doing so, you will prevent developing these kinds of illnesses and your Glofish will live happily in the tank!


In this article, we have provided a complete guide on how to care for Glofish. It is a first-ever genetically engineered fish that fascinated a lot of people and they have been tank-raising it for a long time.

We have noted the key factors in order to rear Glofish successfully and as you can see, they include feeding them with the right diet, knowing the breeding process, assembling your aquarium accordingly, and preventing different kinds of diseases.

You should not be worried if you are just getting familiar with this hobby as Glofish are very easy to care and we hope this article will be an excellent starting point for you.

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