Why Is My Glofish Not Eating? {What Is The Best Glofish Food?}

Are you worried that your Glofish isn’t eating? Is this glofish thin, dull or dying? In this article, we’ll try to shed light on how to get your glofish to eat to the right food under the best conditions to promote its survival.

Why Is My Glofish Not Eating? Glofish enjoy eating in a clean tank, but one that isn’t cycled properly builds up too many toxins and limits their appetite. Glofish should be kept comfortable in groups of 5 or more, while the food choices you make and how much you’re feeding them could help to ignite their appetites. 

What Is Wrong With My Glofish?

Your glofish should love to eat. They are usually hungry or peckish all the time. It’s up to us to limit the amount we give them, or else they’ll just keep eating. If you notice your glofish giving up on food, then there’s something wrong.

Here are some possible reasons:

  • They don’t like the food offered
  • They are stressed
  • There could be an illness
  • The environment is not suitable
  • Aggressive tankmates
  • Loneliness

All fish enjoy variety in their meals. Feeding them the same thing over and over may produce a response to ignore it until something better is offered. Stress results from poor water conditions or aggressive tankmates. Make sure the tank is not too small. Anything less than 10 gallons will be a challenge.

Illnesses result when their immune systems weaken or the tank is not properly cycled and clear of ammonia. Glofish like to shoal in groups. One glofish alone may lead to sadness and lack of appetite or energy. They are not big fish so any other tankmates that are larger can bully them.

What Are The Best Foods To Feed My Glofish?

Glofish would like a varied diet to support them as omnivores. You can choose from:

  • live food
  • flakes
  • pellets
  • frozen food

Be sure to look into which foods are higher in beta carotene. Carotenoids are known to help promote their vibrant colors. Certain blends of flakes or liquid supplements can boost their beta carotene intake to help brighten them up.

You want your glofish attacking the food within seconds and removing leftovers quickly if they aren’t eating. Any remaining food is sure to add to your tank’s bio-load and increase ammonia levels.

Try these foods out to ignite the appetite of your Glofish:

  • bloodworms
  • brine shrimp
  • daphnia
  • spirulina or algae wafers

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How Often Should I Feed My Glofish?

The supplier or representative at your local fish shop will most likely recommend two feedings a day. If you notice that your glofish isn’t eating, then you might be following recommendations, but still overdoing it.

  • Restrict feedings to once a day.
  • Reduce the amount of food.
  • Feed only 5 days a week with 2 days off.
  • Keep the water clean.

Do this for 2-3 weeks and see if it improves the appetites of your glofish. They will not go hungry and many fish keepers have had success with this method to prolong the lifespan of their glofish.

What Do My Glofish Need To Be Healthy?

Your glofish could benefit from supplemented carotenoids to brighten their color, but what if they are not eating at all?

Look into the tank’s ecosystem as the possible culprit for the loss of their appetite.

  • Check water parameters (ammonia + nitrites = 0 ppm)
  • Perform 50% water changes weekly
  • Maintain an optimal temperature at 72-82°F
  • Get a larger tank is possible
  • Make sure the tank’s nitrogen cycle is patiently performed

A water testing kit will give you the numbers you need to be checking for optimal water parameters. Water changes will help to clear up ammonia, but if they continue to spike then the nitrogen cycle was not performed long enough.

Cycle the tank over 4-8 weeks and add your fish back into the tank slowly. The toxins are rising or spiking and the tank can’t handle it without the beneficial bacteria gained from a healthy tank cycling.  A 10-15 gallon should be fine for 6-8 glofish, but a 20 gallon tank would be better.

How Long Can Glofish Survive Without Eating?

Your glofish are not the hardiest of fish, but they can survive up to 3 days without eating. Adding bloodworms or brine shrimp may not work if your glofish was raised on flakes alone.

Go back to basics and try to coat the flakes in vitamin based liquid supplements or liquid garlic. They are meant to build up the immune systems of fish that need it and the garlic flavor could also liven up their appetites.

Is My Glofish Stressed?

Your glofish may be abstaining from feedings because it’s stressed. Look for the following symptoms:

  • excessive hiding
  • gasping for air
  • darting around erratically 
  • lethargic or sluggish
  • dull or pale color
  • bulging eyes
  • fin damage

The water quality or aggressive tankmates could be causing these symptoms. Be careful because they will lead to a decreased immune system that will invite illness.

A lack of appetite is a sign of stress as well. Perform water changes and remove aggressive tankmates. Make sure the tank is cycled and it’s large enough to reduce any stress involved from overcrowding.


Glofish have healthy appetites when they are comfortable. They will enjoy the company of more glofish in a tank where they can shoal together or swim freely. Larger tankmates and increased toxins through ammonia from excess waste or an improperly cycled tank is sure to decrease their appetites.

If your tank is healthy and your glofish still do not want to eat, reduce feedings to once per day and take a day or two off per week for a little while to see if this livens their appetite. You will not be doing a disservice and you could help prolong their lives by not overfeeding.

Add more carotenoids, vitamins through supplementation or addition of live, frozen or liquid solutions that will boost their immune systems and vary their diets along the way.


We hope your Glofish enjoys its next meal and thank you for taking the time to care enough to research to find solutions. Take a look at all of our Glofish articles for anything and everything to do with caring for them. 

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.

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