How to Care for Glofish Tetra?

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If you love tetras and you love Glofish equally, it’s only natural for you to consider getting Glofish tetras eventually since they combine the best of both worlds.

Fortunately for you, there aren’t any meaningful differences between Glofish and normal tetras other than their exquisite coloring.

Tetras are small fish, only growing up to 1.5 inches, and are very easily recognizable. The neon tetra displays 2 dominant colors, neon blue and red, in the rear side of the body, towards the tail.

Tetras are peaceful, hardy, and show low maintenance requirements, making them ideal for novice fish keepers.

But what makes Glofish tetras different, and what should you know about this species? Let’s find out!

What is a Glofish Tetra?

Glofish tetras belong to a unique category of fish, the Glofish, which encompasses 5 species so far. These are the tetras, zebra danios, tiger barbs, bettas, and rainbow sharks.

All these species are identical to their normal counterparts except for their exquisite coloring.

Glofish have been genetically engineered to display fluorescent colors by manipulating their genetic code and mixing it with a gene coming from a species of jellyfish.

The jellyfish produces what’s known as the Green Fluorescent Protein, allowing it to glow in the dark or specific lighting conditions.

The purpose was to design a species of fish to glow in the presence of specific environmental toxins related to human activities.

Needless to say, Glofish caught on thanks to their unique appearance and astounding coloring and glowing. The tetras are but one of the 5 species currently available to buy, should you be interested in getting some.

As a must-know note, Glofish aren’t meant for profit selling because they belong to a trademark category of fish.

You can only purchase them from certified shops and cannot breed them for profit, only for personal use.

How Long Do Glofish Tetras Live?

Glofish tetras can live between 3 and 5 years, which is natural for tetras living in captivity. Their lifespan will vary depending on factors like diets, environmental factors, social structure, disease, genetic makeup, etc.

In other words, you can prolong your Glofish tetras’ lives if you provide them with optimal care and maintenance.

Keeping them in groups of a minimum of 6 individuals is ideal in this sense. Tetras display schooling behavior, and keeping them alone will quickly degrade their mental state and, ultimately, their health and lifespan.

How Big Do Glofish Tetras Grow?

Glofish tetras will only reach up to 2.5 inches, which isn’t that different from normal tetras. This is their adult size, which means that tetras are rather slow growers.

They will reach ¼ inches in their first 2 months of life, after which their growth rate will drop even further.

So, don’t expect adult-sized tetras for a while.

Are Glofish Tetras Aggressive?

Tetras are very peaceful and calm schooling fish that like to keep to themselves. They are ideal tank mates for fish species similar in personality and environmental requirements and will rarely get aggressive.

In most cases, tetras display aggressive behavior towards one another. Male tetras, in particular, may become aggressive towards other males due to their territorial instincts, which happens when there are multiple males living in a small environment.

Male tetras may also grow aggressive during the mating phase, when competition over females, combined with higher testosterone levels, will exacerbate their aggression. However, these issues are easy to fix.

Keeping tetras solos or in pairs can also boost their aggression and affect their state of mind.

Tetras are schooling fish and like to live in more extended populations. In essence, the more tetras you have, the better.

To prevent any unexpected aggressive behavior from your tetras:

  • Keep your Glofish in larger communities of at least 6 individuals
  • Limit the number of males so that you have 1 male for every 2-3 female tetras
  • Provide the aquarium with a variety of plants and aquatic decorations designed to keep your tetras calm and happy
  • Only pair tetras with similarly peaceful and calm fish species, if you’re aiming for a community setup

These strategies should minimize tetra aggression which is very low, to begin with.

How Many Glofish Tetra Should You Get?

Whether you’re a beginner or an experienced fish keeper, getting at least 6 tetras is necessary to set the foundation of a healthy and thriving population.

I would suggest even more than that, provided you limit the number of males. The reason for that is easily explained by looking into the tetras mating phase.

Male tetras perform a courting dance designed to attract the female’s attention, and this can last for a while. If there are several other males around, they will look to intervene and also try their luck at the female.

This will soon devolve into fighting since the males’ high testosterone levels will fuel their aggression.

Having at least 2 females for every male will minimize the risk of aggression since there will be plenty of females for everyone to court.

Depending on your tank’s size and experience level, I would even recommend more tetras, as larger schools tend to be more peaceful overall.

What is the Best Tank Size for Glofish Tetras?

The size of the tank differs based on how many tetras you’re getting. As a general rule, one 2.5-inch tetra requires around 2 gallons of water in terms of space.

A school of 5-6 tetras should to fine in a 10-gallon tank, but I would suggest a bit larger one. You also need to consider the additional equipment that typically should go in a Glofish tank, depending on the fish species.

For tetras, you need to include some plants, rocks, and various decorations that are fit for a medium-sized school. Tetras feel more comfortable in a natural-looking environment, as it keeps them happy and calmer in the long run.

You also need room for essential equipment pieces like a heater and a filtering system. All these pieces will decrease the amount of space your tetras will enjoy, so I recommend providing your Glofish tetras with more than 2 gallons of water per fish.

Do Glofish Tetra Need Filtration?

They don’t need it in the sense that they will die without one, but in the sense that it improves their quality of life.

The filter is necessary for several reasons:

  • Dilutes ammonia – Ammonia is the natural byproduct of fish waste and decaying organic matter, whether plant or animal-based. Overcrowding your tetras will increase ammonia simply by the virtue of having more fish to produce waste in a too-small space. Overfeeding will also boost ammonia due to the food residues sinking on the substrate and decaying there, altering the water’s chemical composition. The filter removes floating particles and cleanses the water, which controls the ammonia levels.
  • Enriching the tank’s biofilm – Every aquarium has a stable biofilm, consisting of cultures of billions of beneficial bacteria. These microorganisms feed on ammonia and nitrites and turn them into nitrates, which aren’t as toxic as the former components. These beneficial bacteria usually form on the substrate but will thrive inside the filtering system. Without a filter, your tank’s biofilm will be significantly less effective.
  • Cleaning the water – The filter traps most particles floating in the water. This will make the water appear cleaner and clearer because it is.

Without a filter, you will just need to perform more maintenance work, more frequent water changes, and more tank cleaning.

The filter will cut down your involvement significantly, although you still have a part to play in keeping your tetra’s environment stable.

Ideal Water Parameters for Glofish Tetra

Tetras are tropical fish and, despite the Glofish version not existing in the wild, it shares most of its genetic code with the non-engineered tetra species.

So, it’s safe to say that whatever applies to normal tetras also applies to the Glofish ones. With that said, Glofish tetras enjoy tropical water temperatures of around 72 to 80 F, a 6.0 to 7.0 pH, and water hardness of 2-10 dGH.

Naturally, these values aren’t set in stone. They allow for some variation because tetras are hardy fish but don’t take their adaptability for granted. Sudden or massive variations in temperature or other water parameters may cause your tetras discomfort and even health issues in the long run.

I suggest monitoring essential parameters like temperature, pH, and ammonia levels to make sure everything remains within the ideal charts.

What do Glofish Tetra Eat?

Tetras are omnivorous fish, which means that Glofish tetras fall into the same category. They will consume a multitude of foods, including pellets, flakes, food chips, and frozen and live food.

You can either feed them specialized fish food, homemade meals, or a mix of both for the best results.

There are 3 things to remember when feeding your Glofish tetras:

  1. Diversity is necessary – Tetras require both plant and animal-based nutrients. Provide them with a mix of food sources, including vegetables, brine shrimp, microworms, bloodworms, wafers, etc., to help them remain healthy long-term.
  2. Avoid overfeeding – You should only feed your tetras up to 2 times per day and never more than what they can eat within 1-2 minutes. Anything more than that will result in food waste accumulating in the tank water and decaying with time. As we’re learned, this is one of the main ingredients of ammonia poisoning.
  3. Avoid foods from unreliable sources – You shouldn’t feed your tetras insects, works, or plants you collect from your backyard or other unsafe areas. Doing so may result in feeding your tetras’ contaminated vegetables containing various environmental pollutants or pesticides, which can prove deadly. Wild worms and insects may also carry various parasites that could infect your tetras, leading to numerous health problems or even sudden death.

If you’ve decided to provide your Glofish tetras with the best diet, I suggest a mix of commercial fish food and homemade meals. Homegrown food cultures are the ideal choice, especially if you have a larger community of Glofish tetras.

These will ensure a ready-to-eat supply of fresh and safe food for your tetras which you can freeze for later use.

Are Glofish Tetras Hardy?

Glofish tetras are as hardy and adaptable as their non-fluorescent counterparts, which goes to say that they are adept at thriving in a variety of environments. That doesn’t mean that tetras can adapt to any aquatic environment.

For instance, they prefer tropical temperatures, and while they can withstand some temperature variations, they won’t allow for all variations.

Sudden changes in temperature or frequent massive temperature fluctuations will hurt your tetras, and the same goes for all parameters.

Try to keep your tetras’ environment stable which is another way of saying that you need to invest in some reliable equipment, including a heater and a filter.


Glofish tetras are beautiful and energetic fish that will complement any aquatic environment.

You can keep them in both single-species and community tanks as they are peaceful and acceptant of other fish species with similar personalities.

Provide them with optimal living conditions, a balanced diet, and a natural-looking environment, and they will thrive over the years. Just don’t breed them for profit. Other than that, everything’s fair game.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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