How Often Do You Feed Glofish? Will They Explode From Overeating?

Jan 25, 2022

How Often Do You Feed Glofish

Image Credit: Dennis Amith (CC License)

Believe it or not, overfeeding is among the top reasons fish die prematurely. However, underfeeding can be just as dangerous too. There’s no rule carved in stone about how often do you feed glofish. 

But in this article, I’ll shine a light on the most common practices of feeding glofish. 

So, hop on! 

How Often Do You Feed Glofish? 

Most experts suggest giving glofish medium-sized meals once or twice a day. Some hobbyists fast their fish 1-2 days every week to clear their digestive system, which is perfectly normal, too. Nonetheless, 1-2 meals per day is the standard practice. 

How long your glofish can go without a meal also differs according to species. 

For instance, larger and more sedentary fish like glofish sharks can go a bit longer between meals than smaller and active fish like glofish danios and tetras. 

Glofish danios, barbs, and tetras are pretty active fish and have higher metabolic rates than glofish sharks and bettas. 

Therefore, they might benefit from small but frequent meals. 

Take it with a pinch of salt, but there is one golden rule to feeding your fish. It can be overwhelming to figure out the right frequency and portion as a beginner. 

But over time, you will undoubtedly get a much better idea of how much your glofish can eat, how fast it eats, and what it likes the best. 

You can then always adjust their dietary regime. 

Whenever you buy your glofish, I’d suggest discussing feeding practices with the local pet shop experts. They probably know the fish’s needs and wants more than us. 

They will even suggest some good food options for your fish. 

In the wild, herbivore fish forage throughout the day. Thus, they need to be fed more often in the tank – but be mindful about the quantity. 

Luckily, none of the 5 glofish species are herbivores. So, you need not worry about that!

And if you are interested to know more about the specific dietary requirements for each glofish species, check out these articles that cover absolutely everything on the topic. 

Also, if you are curious about how long glofish can go without food and how to keep them fed while you’re away, don’t skip this article! 

How Long Can Glofish Go Without Food? Which Species Can Go The Longest?

How Often Do You Feed Glofish Fry? 

Unlike adults, glofish fry need to be fed several times a day. During this formative stage of their lives, they’re quite vulnerable to starvation, leading to stunted growth and potentially death. 

For that reason, you should give them several mid-sized meals per day. 

And while you’re at it, you should also perform frequent water changes. And clean water is pivotal for their good health. 

Now, before we dive into the nitty-gritty of the right feeding practices, it’s crucial to understand how fish have evolved to eat over thousands of years. 

Keep reading! 

How Do Fish Eat In The Wild?

I know glofish are made in the labs. They’re not found in the wild. However, except for the bright, fluorescent disposition, they’re similar to their original species in every single way. 

So, a fish’s dietary pattern in the wild very much aligns with a glofish’. 

Now, let’s get to the gist. 

In the wild, fish eat whenever they are hungry or find food. If the resources are bountiful, they will greedily eat several times a day. However, if the resources are scarce, they can go without eating for days. 

Therefore, fish are opportunistic feeders. And so are your glofish. 

So, as you can guess, if you offer your glofish some food, they will readily gobble it up even when they are not hungry.

Keep this in mind next time they ‘beg’ for food! 

Now that you understand their dietary instinct, let’s tackle some more frequently asked questions.

How Do Different Glofish Species Eat?

Green glofish tetra
Credit: Dennis Amith (CC License)

There are 5 distinct glofish species, and they have quite unique feeding styles.

  • Glofish bettas are surface feeders. Therefore, they have an upturned mouth that helps skim the water surface for food. 

  • Glofish tetras, barbs, and danios are mid-range feeders. Thus, they have a pretty straightforward mouth that extends from the face that helps collect food as it falls through the water. 

  • And lastly, glofish sharks are bottom feeders. Thus, they’ve evolved to have a downturned mouth that facilitates easy feeding from the bottom surface. 

How Much Should You Feed Your Glofish?

The rule of thumb is to feed your glofish an amount they can finish within 3 minutes. And if you suspect you’re underfeeding your glofish, you can always offer another small offering. 

When in doubt, I suggest underfeeding. Uneaten food is the top reason behind unnatural and harmful spikes in ammonia and nitrite levels. 

However, if your glofish quickly finishes its food in under 3 minutes, it can mean you’re underfeeding the fish. In that case, you can offer some more food. 

I answered this question based on my own feeding practice. But honestly, you’ll seldom get the same answer from two different hobbyists. So it’s a sticking point. 

The answer may vary from 30 seconds to 5 minutes.

And the reason behind this vagueness is that some fish will wolf down their meal within seconds, while others love to take their sweet time. 

Even fish belonging to the same species have different feeding patterns and speeds. 

Lastly, a not-so-common but helpful way to gauge the amount you give your fish is by observing the roundness of their bellies from the side and top views. 

I know this sounds painstaking, but once you get the hang of it, you can tell if the fish is full or not in under 5 seconds. 

And by the way, remove uneaten food using a net or a siphon hose after 5-10 minutes to not pollute the water. 

At What Times Should You Feed Your Glofish?

In the wild, fish eat whenever they find food. In the tank, the best practice is to offer food early in the morning and at dusk. Once again, this rule is not stringent, but it definitely is the standard practice. 

Turn on the aquarium lights at least 20-30 minutes before offering food. This will help ensure that everyone is awake, alert, and ready to devour. 

And likewise, keep the lights on for at least 30 minutes after the nighttime feeding. 

Since none of the glofish species are nocturnal, you don’t have to worry about making arrangements to feed them at night in the dark.

What Are The Signs Of Overfeeding Your Glofish?

The most common signs of overfeeding in glofish are a swollen belly, a lot of poop in the tank, and a lack of interest when you offer food. There will also be piles of leftover food at the bottom laced with fungus, a sudden explosion of snail and worm population, and an unsightly algae growth. 

I find feeding fish almost therapeutic. It’s something I look forward to every day. And naturally, I am guilty of often providing them more than I should. 

Below, I’ll list down the signs of overfeeding glofish in bullets:

  • Leftover food will remain in the tank 10 to 15 minutes after feeding, but the glofish will show no interest in it. 
  • In some extreme cases, uneaten food will have fuzzy and cottony white fungus growing on them. 
  • The water will become hazy and cloudy. It will also give off pungent odors. Foam or froth can also develop on the surface. 
  • Filter media becomes clogged within a matter of a few days after cleaning.
  • Unnatural spike in algae growth despite proper filtration and water changes. 
  • Harmful levels of compounds like ammonia, nitrate, and nitrite. 
  • Prolific growth in snail and worm population. 

Unfortunately, the effects of overfeeding a fish don’t show themselves right off the bat. So while it’s a myth that the fish will explode from overeating, it can very well invite some grave consequences. 

If consistently overfed, your glofish will develop fatty liver disease and constipation. 

And since all those piled-up leftover food will cause a rise in ammonia and nitrite levels, your glofish will be highly susceptible to contracting bacterial and fungal infections. 

As soon as you notice the first signs of overfeeding, siphon out all of the uneaten food, vacuum the substrate, perform a slight water change, and reduce the feeding amount by 50% for a couple of days. 

How To Know If You’re Underfeeding Your Glofish?

If your glofish have sunken bellies or skinny bodies, sport a drab appearance and faded colors, and appear more lethargic than ever, you are probably underfeeding your glofish. 

But here’s the tricky part. These signs aren’t just exclusive to underfeeding. They could also mean the fish is infested with internal worms or parasites. 

Hence, if you are feeding your glofish plenty but they are still not gaining weight, you may want to consult the vet. 

They will most probably recommend an antiparasitic or deworming medication to effectively eradicate unwanted hitchhikers. 

Should You Fast Your Glofish?

Like regular bettas, glofish bettas are prone to digestive complications. Thus, they can benefit from fasting once in a while. On the other hand, nano glofish like tetras and danios have small stomachs. Hence, fasting them may not be the best idea. 

Risks Of Underfeeding Your Glofish

Underfeeding your glofish can be just as detrimental to their health as overfeeding, if not more. To keep the water cleaner for a longer time, we often mistakenly underfeed our glofish.

Diets that are inadequate in protein, amino acids, vitamins, minerals, and essential fatty acids expose your fish to gross malnutrition and high disease susceptibility. 

Let’s have a look at the effects of different nutritional deficiencies: 

Nutrient Deficiency Signs 
Vitamin BStunted growth, low hemoglobin levels, lack of appetite 
Vitamin CEye lesions, impaired collagen formation, dark coloration
Vitamin DSlowed growth rate, lethargy, softened exoskeleton 
Vitamin AAnemia, exophthalmia, kidney hemorrhages, pigmentation 
CalciumSkull deformities, stunted growth, scoliosis, increased mortality
Manganese Disbalanced equilibrium, weight loss, mortality 
IodineThyroid, hyperplasia

Final Words: How Often Do You Feed Glofish?

The general practice is to give two medium-sized meals once or twice a day. 

That being said, there’s no one golden rule to follow. It boils down to your fish’s needs and your convenience as well. 

Generally, large and sedentary fish can go a bit longer between meals. But small and highly energetic fish like glofish danios and tetras will require frequent feedings! 

Recommended Readings!

Do Glofish Need Light At Night? Blue Light Harms Their Eyes?

What Glofish Can Live Together? 2022 Compatibility Guide

How Many Glofish In A 30-Gallon Tank? Answers For All 5 Species!

What Do Baby Glofish Look Like? Photos And Videos!

rohit gurung author at urbanfishkeeping

About Rohit Gurung

My never-ending love and fascination with Aquascaping started when I received a red-eared turtle for my 10th birthday.

Apart from researching and writing, I spend hours gazing at my 3 turtles. And yeah, I bask alongside them too.