Parents of fish would love to pack up their tank and take their aquatic friends on vacation, but that is not possible. So how do you feed your fish while you’re away? Whether you choose a fish sitter, an automatic fish feeder, a vacation fish feeder, or not feeding them at all, you’ll need to do some research and come up with a good plan.
To help aquarists get ready for their trip, we spoke with Dr. Jessie Sanders, DVM, certified aquatic veterinarian (CertAqV) and owner of Aquatic Veterinary Services in northern California, and Dr. , DVM, a veterinarian and the founder of the Wet Pet Vet in New York City, for advice on how to feed aquarium fish while you’re away.
As aquarium owners, we want to ensure our fish are well-fed and happy. But life happens, and sometimes we need to go away for a few days. This leaves us wondering – how long can pet fish live without being fed?
I’ve kept freshwater aquariums for over 5 years and have researched this topic extensively In this article, I’ll share what I’ve learned about how long fish can go without eating
The Short Answer
The short answer is that most adult aquarium fish can survive 1 week to 2 weeks without food before adverse effects set in. However, fish fry and young fish cannot go as long without eating. Some key factors like fish species age and water quality impact fasting ability.
Why Fish Can Go So Long Without Food
In the wild, fish don’t get regular scheduled meals There are times when prey is plentiful, and times of scarcity when they have to endure periods of hunger. Fish have evolved bodily mechanisms to handle fasting
Healthy adult fish maintain reserves of fat and glycogen in their liver. When food isn’t available, their metabolism slows down. Energy from these reserves gets released slowly to supply basic body functions.
Also, when deprived of food, fish undergo protein sparing. Their bodies break down non-essential muscle proteins into amino acids for energy production. This preserves proteins vital for key biological processes.
These adaptations allow fish to withstand lengthy fasts. However, young, old, or ill fish have less robust mechanisms for dealing with starvation.
Impact of Fish Species
While most fish can go 1-2 weeks without eating, some species have greater fasting tolerance. Here are some popular aquarium fish ranked by their ability to withstand starvation:
Can go 2-4 weeks without food:
- Oscars
- Koi
- Goldfish
- Gouramis
Can go 1-2 weeks without food:
- Bettas
- Mollies
- Platies
- Cichlids
- Plecos
Can go 7-10 days without food:
- Tetras
- Guppies
- Corydoras
- Danios
- Barbs
Take these timespans as general guidelines that depend on other factors as well. Don’t purposely starve fish longer than necessary.
Role of Fish Age and Size
Younger and smaller fish have higher metabolisms and lower fat stores. They can’t endure hunger as long as adult fish.
Newly hatched fry need to eat several times per day. Missing even one day of meals can be detrimental.
Juvenile fish should be fed once or twice daily. They can only withstand 2-4 days without food before health decline.
Adult fish have the highest fasting tolerance thanks to their size and energy reserves. Still, don’t deprive them of food for longer than needed.
Impact of Water Quality
Fish in a brand new tank aren’t yet adapted to their environment. The stress of adjusting makes them less resilient to fasting.
In established, stable aquariums with optimal water parameters, the inhabitants are conditioned to the habitat. Healthy water reduces environmental stressors, giving fish better capability to handle starvation.
Providing Food on Vacation
While fish can manage short fasts, you don’t need to deprive them if going away. Consider these feeding options:
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Automatic fish feeders – Programmable devices that release precise amounts of food on a set schedule.
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Family/friends feeding – Ask someone to come by and feed the fish. Provide detailed instructions to prevent overfeeding.
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Vacation feeder blocks – Slow-release blocks that dissolve over days/weeks. Can pollute water with excess food if not monitored.
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Fast fish before leaving – Stop feeding a day or two before departing to reduce waste production in absence.
Weighing the Pros and Cons of Fasting Fish
As we’ve covered, most fish can survive over a week without eating with minimal ill effects. So why not just let them fast while we’re gone? Here are some pros and cons to consider:
Pros:
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Gives the aquarium a break from extra waste and nutrients added via food. May help stabilize nitrates and reduce algae growth.
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Helps prevent overfeeding by caretakers unsure of proper amounts. A common problem when others feed your fish.
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Fasting for short periods may aid digestion in some chronically constipated fish prone to bloating and swim bladder issues.
Cons:
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Sudden starvation is stressful. Gradual fasting over a few days is better if depriving fish of food.
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Young fish don’t tolerate fasting well. Missing meals can impair growth and immunity.
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Fish with existing illness or metabolic issues may decline rapidly if starved for over a week.
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Fasts longer than 2 weeks risk protein and muscle loss even in healthy adult fish.
The Verdict
In most cases, leaving your fish without food for a weekend or week-long trip is fine. Adult fish in an established aquarium can handle brief fasts. But extending this to 2 weeks or longer, or depriving fry and juveniles, can be risky.
For peace of mind, utilize automatic feeders, friends, vacation blocks, or fast the fish prior to leaving. This ensures your fish don’t miss too many meals while you’re away!
Hire a Casual Fish Sitter
Another idea is to ask a family member, friend, or neighbor to check on your aquarium fish. The best people for this are those who have simple fish tanks (think goldfish or betta fish) and those who are going on short trips. If you leave your fish for more than a week, you might need to change the water. This is something that experienced fish sitters should do, but a trusted friend could do it if they were given clear instructions.
Also keep in mind the worst case scenario emotional cost. If something goes wrong with the fish tanks while you’re away, you don’t want that to hurt your relationship with that person. Consider hiring a pro if you’re worried about that possibility.
As a pet sitter, it shouldn’t be hard for friends, family, neighbors, or anyone else who wants to watch your aquarium fish but has never done it before. The goal is to make things as easy as possible for them.
- Keep it simple. For example, don’t ask them to hatch and harvest brine shrimp or fill up your CO2 tank. Stick to checking how the tank looks, feeding your fish, and, if necessary, checking the water level.
- Clearly set expectations. Tell them ahead of time what they need to do to take care of the fish and leave a note with clear instructions.
- Portion out the food ahead of time. Put it in bags with labels that say which day each serving should be eaten. You can put sticky notes on the aquariums that tell you when and how much to feed them if you have more than one.
- Prepare extra water. Evaporation can cause the water level to drop over time, so it’s a good idea to have a bucket of water with a water conditioner ready next to the aquarium for when someone comes to watch your fish.
- Leave a phone number. When people need to get in touch with you, make sure they know how to do so. To be safe, you can also leave the number of a skilled fishkeeper who might be able to help. If you don’t know any experienced fish keepers, leave the name and number of your favorite aquarium store. Let the manager of the store know what you’re doing so they can help you get in touch with your fish sitter if you need to.
- Hide extra food. People who don’t know much about fish might think they’re still hungry after a meal and give them too much food. “Unfortunately, you’ll have a lot of problems if you feed fish too much while you’re away and don’t keep the water tested,” Dr. Sanders says.
5 Options for Feeding Fish While on Vacation
Here is an in-depth look at your aquarium fish care choices, including how much they cost, what each one entails, and what you should think about before making your choice.
How long can a fish go without food in an aquarium?
How long can a fish be without food?
You can take a few approaches when you know your fish will be without food for more than 3 days. We do not recommend that any action regarding food be taken in a fasting period of fewer than 3 days, except in fish that will reproduce or are in the growth phase.
Is it good to eat fish?
Fish is one of the healthiest foods on earth. It is loaded with important nutrients such as protein and vitamin D. Fish is also a great source of omega-3 fatty acids, which are very essential for body and brain growth and development. Some fish are high in mercury, which is related to brain developmental problems. Eating fish lowers the risk of heart attacks and strokes. Omega-3 fatty acids in fish may combat depression. Fish and fish products are the best sources of vitamin D. Eating fish has been linked to reduce the risk of type 1 diabetes and several other autoimmune diseases. Eating fish protects vision in old age, preventing age-related macular degeneration(AMD).
How long can baby fish live without food?
Baby fish cannot live without food for more than a day or two. A well-maintained tank may be left for extended lengths of time than a newly installed aquarium. The tank mates in an ecologically balanced aquarium have previous experience surviving in this habitat.
How long can ornamental fish live without food?
If your fish is healthy and the aquarium is in good condition, most ornamental fish species can survive up to 5 days without feeding. But the safe time window to leave your fish without food is up to 3 days; after that, the animal already shows signs of nutritional deficiencies.