How long can a fish go without food?


You’re having a fun day outside, no work tension, it’s just you and your friends enjoy. You’re chit-chatting, and suddenly you remember you have a fish at home. You fed him in the morning, but now it’s late in the night. Now you’re stuck there thinking about your hungry fish.

Your mind is stuck on how long can a fish go without food? This might be bothering you as you might not be planning to go home soon. Well, how long your fish can survive depends on his or her age. Young fishes might not go on longer without feeding. In contrast, healthy adult fishes can survive a week without eating anything.

How Long Can Fish Go Without Feeding?

Fishes living in open waters don’t have many options for eating daily. As a result, some of them had to go without eating for a very long time. So that doesn’t mean they’ll die within moments of being hungry.

A pet fish or a healthy aquarium fish can go without feeding for 3 days to a whole week. Of course, we’re talking about an average fish here. Certain species of fish can survive for 2 weeks without eating anything.

An adult, whether in an aquarium or nature, has enough fat reserves and body mass that allows them to skip a meal or two for some days. Thus, you can freely plan a long weekend away from your home and don’t worry about feeding your fish.

We often forget that our pets come from environments where they don’t have food to eat daily. As a result, we tend to overfeed them when in reality, fish can be perfectly fine for some days without eating anything.

Fasting Capacity of Different Breeds of Fish

Though the skin of fish is hard in general, its ability to fast varies depending on its breed. Here’s the list of fasting capacity of different fish breeds:

  • African Cichlids: 10 days
  • Angelfish: 1 week
  • Barbs: 14 days
  • Betta: 1 to 2 weeks
  • Corydoras catfish: 2 weeks
  • Danios: 14 days
  • Discus: 14 days
  • Goldfish: 10 days
  • Gouramis: 2 weeks
  • Guppies: 7 to 10 days
  • Koi Fish: 2 weeks
  • Loaches: 10 days
  • Mollies: 2 weeks
  • Oscars: 2 weeks
  • Platies: 10-14 days
  • Plecos: 10-14 days
  • Rasboras: 1 week
  • Swordtail fish: Max 14 days
  • Tetras: 10 days

Despite the long fasting capacity of fish, it is never advised to keep your pet fish hungry for this long.

Factors to Consider When Your Fish is Hungry for a Long Time

Here are a few factors you can keep in mind if you don’t feed your fish for a long time.

Carnivorous or Herbivorous

Herbivorous fishes consume algae and plants. Unfortunately, what they consume is harder to break; that’s why they need to be fed from time to time to give them proper nutrition.

Carnivorous fish like Betta survive on meat, and they go without food for many days because of not enough prey. Therefore if you keep them as pets, they can go on longer without feeding.

Age and Size

As fish ages and grows in size, its skin becomes harder, which means extra fat reserves and body mass to use in times of hunger. For example, Gourami fish can survive without food, more than a small Guppy fish.

If you’re going out for a long weekend, here’s a trick you can use to lose the appetite for your fish. Set the light timer for 6-8 hours instead of 12 hours. This will trick your fish into thinking shorter day time and fish are not very active at night. So in a dark environment, they’ll be asleep, so there is no more need for food.


Smaller fishes tend to be more active as they don’t have high body mass or fat reserve to slow their moving ability. On the other hand, big fishes have slow metabolism because of their body mass.

Higher metabolism means food will digest faster, and your fish will need food more often. Similarly, lower metabolism can mean your fish will digest food slowly and need food at long intervals.

How to Keep Your Fish Fed While You’re Away?

Automatic Feeders

Now that you know your fish can survive a little longer than you think without food, you can easily go on a vacation. But if you don’t want to take the risk of keeping your fish hungry, you can simply use an automatic feeder to keep your fish fed.

Automatic feeders help you control the amount of fish food and serving time. You’ll rest assured that your fish is fed on time and stays healthy. Do your research before buying an automatic feeder, as some of them can overfeed your fish.

Fish Sitters

It’s understandable if you can’t afford an automatic fish feeder, you can simply ask someone to feed your fish. Take the help of a friend, relative, or neighbor to keep your fish fed while you’re on vacation.

You also get an extra advantage over fish sitters over automatic feeders. They can keep your fish tank clean or treat an ill fish, doing things that an automatic feeder can’t do. You can also check on your fish by video calling or asking for photos.

Food Blocks

They might look weird, but they are the inexpensive and best way to feed your wish. They can last for weeks and don’t require any timer settings.

However, there’s a disadvantage to using food blocks too. They release nutrients into the water slowly but continuously. So your fish might be full, but the food block will keep dissolving.


You’ve understood that fish can go on without feeding for 3 days to 2 weeks, depending on their breed and other factors. However, the range of days can vary a little depending on your fish’s temperature, diet, and metabolism.

But you can rest assured as your fish will be perfectly fine without food for at least 2-3 days. After that, you can feed your fish with any of the above methods if you’re not coming home soon. As long as your fish is healthy, it can be fine without food.


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