Do Glofish Lose Their Color? {Can They Get It Back?}

Are you noticing your glofish losing color? Will this color ever be able to come back or is your glofish getting old? In this article, we’ll find out if glofish lose their color and what we can do about it.

Do Glofish Lose Their Color? Glofish are not meant to lose their color. They are manufactured through genetic engineering to maintain their color for their relatively short lifespans. Stress, overcrowding, poor water quality, old age or improper nutrition could affect their vibrancy and cause them to lose color. 

Why Did My Glofish Lose Color?

Your glofish is injected with DNA from other animals and marine life including colorful jellyfish to give them eye popping fluorescent colors. The manufacturers of this technology to produce captive bred glofish ensure that their color will last a lifetime.

Glofish live around 3 years at optimal health. The problem lies in the their living condition. Here are some reasons why your glofish may have lost its color:

  • stress
  • lack of nutrients
  • overcrowding
  • aggressive tankmates
  • small tank
  • lack of school or companions
  • poor aeration
  • too cold or too warm temperatures
  • spikes of ammonia and nitrites

1. Stress And Food

Stress is the leading cause of most issues leading to poor health. A pale glofish that has lost its color is exhibiting signs of stress. Brine shrimp, bloodworms, daphnia should be included as part of their weekly meals to enhance their nutrition and color.

2. Tanks, Tankmates and Overcrowding

Tanks that are too crowded may get messy and hostile. The bigger fish will exert their dominance and glofish will expel their energy as a school to defend their territory or retreat in fear. Both reactions will lead to stress and possibly the loss of color.

Consider a larger tank if possible. 20 gallons for 6-8 glofish should be the minimum. Although many people consider 10 gallons to suffice for a small school of glofish, you can prevent color loss of other indications of stress with more space.

3. Companionship and Schools

A glofish without a school to provide comfort and safety in numbers is not recommended. Keep 4-6 glofish at the very least and add more if your tank can hold it. When glofish die, the remaining companions could feel stress due to their shrinking numbers. It’s best to replace those who don’t make to their full lifespan.

4. Water Quality and Oxygen

Oxygenate your tank and allow for surface irrigation to take place when the water is being pumped. Add an air pump or air stones to circulate the oxygen. Keep your tank clean and monitor the levels to ensure that ammonia poisoning is not occurring which could lead to discoloration.

Glofish need the water temperature to remain between 72-82°F. If the water is too warm or too cold, they will undergo stress that could be lethal. At first, it may be a noticeable loss of color. At worst, the stress will lead to illness or possible death.

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What Colors Do Glofish Come In?

Glofish are a trademarked type of genetically engineered fish. They are not supposed to be injected with dyes. The source of origin could be doing something “fishy” and injecting zebra fish with dyes that do not last long enough and poison your glofish over time.

Try to buy glofish from reputable sources. The originally trademarked colors are as follows:

  • Starfire Red®
  • Cosmic Blue®
  • Electric Green®
  • Galactic Purple®
  • Sunburst Orange®
  • Moonrise Pink®

Why Is My Glofish Turning White?

A sick, old or dying glofish will have less blood circulation and cause it to turn white.

Some glofish are injected with dyes to give it their color. Others are genetically modified which may lead to a shorter life or loss of color over time.

There are many reasons why your glofish could be turning pale, transparent or white in color. The following reasons are most common:

  • poor water quality
  • scared or bullied glofish
  • old age
  • improper nutrition
  • lack of carotenoids
  • overcrowding
  • too much light
  • lack of oxygen

We start by testing the water parameters and making sure the pH is between 6.0-7.5 and the water temperature is between 72-82°F.

A scared or bullied glofish could also become sluggish, lose its appetite and its poor immune system could lead to slow blood circulation causing it to turn white. Old age or this genetically modified color that could be because of injected dyes that might be wearing off.

Foods or supplements that are high in carotenoids will help to bring vibrancy back to your glofish. The tank lights could be dimmer and an air stone could help to aerate the tank further to promote more oxygenation leading the better color vibrancy.

Make sure the tank is not too small and overcrowded. A 20 gallon tank will lead to better results for active glofish to remain comfortable which promotes better colors that won’t fade so soon with old age.

Are Glofish Hardy?

Glofish are not as hardy as goldfish, but beginners can give it a go to provide enough care without feeling overwhelmed. Children love glofish and will help introduce them to a lifelong hobby to care for fish that are much more challenging to keep than glofish.

They are not aggressive if their tankmates don’t challenge them for territory or chase them because of their smaller size. They can be fed flakes, pellets and frozen foods.

Keep the water quality pristine with no spikes in ammonia with temperatures between 72-82°F and your glofish should be happy for the next few years.

Old age could lead to the loss of vibrant colors, but the manufacturers claim that they will not lose their color throughout their entire lives. Our hair turns gray and we lose pigmentation at older ages. It’s easy to accept the same for glofish when they reach old age as well.

How Can I Make Glofish Glow?

  • black lights
  • carotenoid rich foods
  • water changes
  • dark substrate

Glofish don’t actually glow in the dark. They have fluorescent colors by splicing their DNA with vibrant colors that come from other animals like jellyfish. If you want your glofish to demonstrate their full color potential, consider dimming the lights and using a black light instead.

The black lighting will make their color pop out much more. You should also make sure they are eating enough color enhancing foods high in carotenoids. Keep the water clean with weekly water changes at 10-25% if there no issues.

If you notice they are losing their color, rule out ammonia poisoning by performing larger water changes and keeping a clean substrate. You can also change the substrate for a dark color which will highlight their fluorescent colors under the black lights.

Why Are Glofish Colorful?

Glofish are genetically engineered. Their genes are spliced from other animals and fish to give them eye popping fluorescent colors. Sometimes they are injected with dyes making them “juiced fish”. This term refers to dyes enhancing coloration, but they are detrimental to the longevity of your glofish.

The dye is basically a slow killing poison, but it could wear off before the end of their lifespans. An older glofish could lose its color because of their age or the dye has worn off.


Zebrafish embryo gene modification has led to bright fluorescent colors in glofish to look stunning and vibrant. Black lighting contrasted by dim outside lights near the tank will help to enhance the color spectrum. They may lose color with old age or illness. Accept the former and treat the latter with better water quality, more water changes and ideal temperatures.

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.