How Long Can Fish Go Without Food in an Aquarium?

Fish feeding in our aquarium is a regular thing that is among the most enjoyable aspects of the hobby! You have control over your aquarium up to the point that you need to leave city for a couple of days. Sometimes, our normal schedule is interrupted and we aren’t able to ensure that our pets are fed. The question that comes to our minds: “how long can fish go without food?”

Are your fish able to survive a few hours without being fed? Can the aquarium be able to survive by itself for the duration of a week? If so, just what is the longest time the pet fish go without food, and can they become sick during this time? Can you avoid starving them when you leave to go on your vacation?

How Long Can Fish Go Without Food or Sustenance?

Wild fish aren’t able to eat every day. Certain species experience long periods of time without eating any food.

For instance, the female mouth-brooding African Cichlid can go for up to a month without eating while holding baby fry in her mouth.

In that regard here’s how long an average freshwater fish will go indefinitely without food:

A healthy, mature aquarium fish could go between 3 days to 1 whole week with no eating or taking in any food. Certain species of fish can last for longer than 2 weeks without eating.

In nature as well as in an aquarium a mature fish is able to maintain enough body mass and fat reserves to skip a few meals every now and then.

So, if you’re planning a weekend away then there’s no need to fret about whether your fish will be able to survive even without having been fed.

We often overfeed our animals. We forget that they are from environments that don’t provide them with regular meals.

In regards to fish fry, however, this isn’t the scenario. When fish are born, they must eat several times a day.

Nutrition plays a crucial role in building up bone strength.

Not feeding the baby fry enough may result in deformities as well as sickness or even death.


While fish are hardy in general, however, their fasting tolerance is different based on their breed.

We’ve created an overview chart to help you understand the individual fasting tolerances of a few freshwater fish. Look over the chart which shows the days that popular freshwater fish survive without food:

The Type of Fish You Can Keep:The Period It Can Survive Without Food:
Betta1 to 2 weeks
Goldfishup to 10 days
Corydoras catfishup to 2 weeks
Guppies7 to 10 days
Swordtail fishup to 14 days
African Cichlidsup to 10 days
Platiesfrom 10 and 14 days
Molliesup to 2 weeks
Angelfishup to 1 week
Rasborasup to 1 week
Tetrasup to 10 days
Plecos10 to 14 days
Oscarsup to 2 weeks
DaniosMaximum of 14 days
Koi Fishup to 2 weeks
Barbsup to 14 days
Discusup to 14 days
Loachesup to 10 days
Gouramisup to 2 weeks
Overview Chart on Fasting Tolerances of Some Freshwater Fish

The above list is based on discussions I had of the list with fellow fish keepers with hands-on experience as well as my personal observations of the fish in these lists.

In spite of all the evidence suggesting that fish have greater fasting tolerance we believe it is not a good idea to feed your pet with no food all day.

It’s a risky venture and you could be liable to lose your nipper acquaintances.

While no one is able to precisely define the amount of time the fish will live without eating, there are additional factors you might want to look into.

Are Your Pet Fish Herbivorous or Carnivorous?

The first group consumes vegetables and algae. The plant material consumed by herbivores is difficult to break down and they require food more frequently to get enough nutrients.

A great illustration of aquarium herbivores is certain kinds of plecos as well as the otocinclus as well as other species of fish that eat algae.

Carnivores like Betta Fish eat meat and often go long periods of time without eating out in nature as a result of a failed hunt for prey. Thus, they can endure for long periods without food.

What are the Size and Age of Your Fish?

Fish that are larger and older are more durable since they possess sufficient body mass and fat reserves to be able to utilize in the event of prolonged periods of hunger.

For instance, Gourami fish stay longer in the water without food than smaller Guppy fish.

There are a few tips that you can try prior to leaving, which can help to decrease your appetite for fish.

It’s a fact that the majority of fish do not eat at night.

The user can adjust the timer for light at 6 or 8 hours, instead of 12 for instance.

The shorter daylight hours will limit their physical activity as well as their requirement for food.

Another method you can employ is to gradually reduce the temperature of the tank.

Be cautious not to reduce it over 2 degrees and do make sure that the change is gradual.

In the end, you would like to speed up the speed of their digestive processes, not to take these animals off to the North Pole.

It’s a Great Method to Feed Starving Pet Fish While You’re on Vacation

“What about the fish?” This is the issue that every successful aquarist contemplates as they plan their vacations. It is possible to bring fish with you, however, this isn’t practical nor suggested.

Like other types of pets, fish are required to remain at home while you get away from the routine. Therefore, you’re faced with the dilemma of what your fish will fare when you’re away whether in the care of someone else or on their own.

If you go through your mental list of last-minute items when you get to the airport and back, the fishing aquarium shouldn’t be among them. If you’re planning that you will be returning to a healthy fish after the conclusion of your vacation it is essential to prepare the required preparations prior to when you go. The longer you’ll spend away, the more time you’ll need to prepare.

The fact that marine life is tougher than we think, you can be confident that the idea of leaving the aquarium without food items for an entire weekend will not be a problem.

If you’ve got a lengthy vacation scheduled, you’ll have to ensure that your fish are taken care of during the time. Here are a few of the most popular ways to make sure your fish don’t require going without food!

Automatic Fish Feeders

The best method in order to feed the needs of your pet fish while you are away or during your vacation is with the automatic feeder.

With this device, you’ll have control over your food schedule and serving amounts.

So you are sure that you are not letting your fish just be able to survive, but also live healthy even in your absence.

Automatic fish feeders are the tool of choice in this case. They store food items that have been prepared in the hopper which can also be set to dispense the contents as often or as little as you’d like.

I strongly recommend keeping an automatic feeder on hand a few days prior to your trip so that you can test the system out and ensure it works correctly. Certain feeders are capable of only dispensing only one kind of ready-to-eat food (i.e. only pellets or flakes) therefore be sure to select carefully.

Moisture-Proof Electric Auto Fish Feeder With Timer, Food Dispenser

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  • Programmable: The timer of AquaBlue allows you to set up to 4 automatic feedings per day.
  • Different Fixed Methods: The feeder has 2 install methods for you to choose from.
  • Moisture Prevents Design: Moisture-resistant hopper keeps your fish food dry, won’t be jammed or get wet.
  • You Can Easily Add Food: You can easily decrease or increase the amount of dispensed food.
  • Large Food Capacity: 200ml capacity

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The Torlam is an even more versatile model that offers more options to allow for flexible operation. It is calibrated to provide double or triple feeds at a specific time of the day. For instance, you can program that it will drop one tiny, single serving of pellets in the evening for your plecos; however, you can also provide the community a triple feeding in the afternoon for the entire community.

When you get back home and are back home, you can leave the appliance in place but make use of your hand override button to have the pleasure of personally feeding your fish. However, should work take you away then the Torlam Auto Feeder can dispense food just like normal.

Fish Sitters

The idea of having a relative, neighbor, or friend drop in for a visit to feed your fish can be a regular way to ensure that your fish eat correctly.

Fish sitters also can accomplish things that automatic feeders cannot do, for instance, remove a fish that’s died during your vacation to ensure it does not rot and cause more issues. Contact you for information, photos of the tank, and other things.

I prefer if my fish sitter is knowledgeable about aquariums, so it’s a good idea to join a local aquarium club or have an acquaintance who is knowledgeable about fish! Anyone who isn’t knowledgeable about fish might underfeed or even more seriously, overfeed.

A competent fish sitter may also carry out tests regarding the pH as well as ammonia levels or dispense medications to sick fish.

There aren’t many things more unpleasant for a return to after a vacation other than green aquarium water, foul smells, fungus-covered food, or ich. Make sure you choose your fish’s sitter to be careful!

Food Blocks

Although they may look odd, food blocks are around for a long time and are an economical and easy method to ensure that your fish is content. They can last for weeks and don’t require directions or calibration on how to work!

Automatic Fish Feeder: API VACATION PYRAMID FISH FEEDER 14-Day 1.2-Ounce

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  • It Supplies food to your fish while you are away for up to 14 days
  • Dissolves slowly. It releases food after a few hours
  • Natural ingredients are included to meet the nutritional requirements
  • Drop one pyramid into the aquarium. Do not use it in a fishbowl or non-aerated or a non-filtered aquarium

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In terms of vacation, feeders are ok. They’re definitely the easiest method to ensure your fish stay fed throughout the course of your trip. But, I’m not using them myself, and I’d caution anyone who decides to purchase one of them due to a couple of reasons.

Food blocks are basically mineralized blocks of vegetable and animal protein. They are made of mineral powder. It slows the release of nutrients into the tank water. While this is a great idea, the issue lies in the fact that this release is not constant.

When your fish ceases eating then the dissolution process continues. Manufacturers attempt to counter this by reducing their nutritional content, which makes sense. But we’re now offering low-quality food for our fish. This idea is better than nothing but far from ideal.

Additionally, many fish don’t even consider the blocks to be food. A lot of community fish, like Guppies and Barbs, are versatile and are willing to eat almost anything.

However, I’d be wary of the use of one of these in a fish accustomed to a huge mouthful of food like Cichlids. Tetras aren’t grazers as well and could not be able to recognize the food block. Therefore, think about the fish you are feeding, your nutritional requirements as well as your vacation time carefully to determine which product is best for you.

When You Return Home From a Vacation

The return home after the vacation is typically bittersweet. It’s difficult to accept that the holiday has come to an end (let’s admit it) however, you’re usually content to be home. But, how did your fish do? It will all depend on the way they prepare them to be in your absence. Even having followed all my suggestions up to now, however, the aquarium could appear a bit less than the experience which could prompt you to figure out why.

The time off is a good opportunity to get to know more regarding your aquarium. If you return home with a messy, smelly aquarium, it could be due to having excessive fish. There’s nothing better than a vacation to prove that you’ve been enthusiastic when it comes to stocking an aquarium.

Perhaps they were fed excessive amounts of fish food during your time away. It’s wiser not to underestimate what amount of food and the frequency of feeding they’ll require when you return and find that your fish is starving but still healthy.

Based on the length of time you’ve been away and how long you’ve been away, you could need to schedule the water change and filter cleaning shortly after getting back. It’s crucial to get your aquarium back to an ongoing schedule and to ensure that it is up to date with maintenance and feeding immediately feasible.

With a bit of planning and preparation With a bit of planning and preparation, your experience of going on a vacation isn’t the life-and-death challenge for your fish or source of stress for you in a time that is supposed to be relaxing. However, despite all the advice I’ve given, my best advice is to avoid overstock in your aquarium and to keep a regular maintenance schedule. Two things that can go far in returning home to healthy fish.

Final Words

Healthy fish can go without food until a period of up to one week, without it affecting their well-being.

We’ve discovered that fish could go between three days to a week without eating before they begin suffering. The exact duration is dependent on the temperature and size, metabolism, and diet.

Instead of experimenting with this, apply any of the three options described above to ensure your fish are fed when you have the prospect of a trip lasting more than 2-3 days coming up. Also, be safe, and will your fish be properly fed throughout the time!

If you are planning for a long time, or are hosting fish fry in the aquarium it is likely that you will need to prepare your trip prior to leaving.

Additionally, it’s recommended to purchase an automatic fish feeder to make sure you and your pet fish can eat regularly even when you’re not there.

Now is the time to go and take advantage of your vacation.


Dibyajyoti Bordoloi is the creator and author of, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.

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