Freshwater fish are one of the easiest pets to take care of and are especially great as a first pet for kids.
However, sometimes we all can be forgetful or have an unexpected event that makes us late for feeding time.
Freshwater fish can go between 3 days to two weeks without food. A fish can go a long time without food added to the tank if there are “leftovers” in the tank or live plants that they can feed off. However, if you have an immaculate tank with babies they may not survive as long.
While inconsistent feeding should be avoided, sometimes it is inevitable.
Read on to learn more about factors that impact the length of time a fish could go without food and what to do if you are planning to be away for a few days.
Age of Aquarium Setup
Surprisingly, the age of your aquarium can impact how long your fish can go without food.
In an established tank, your fish are accustomed to their environment and are generally stress-free and comfortable.
They are used to the other fish in your tank and will feel at ease which leads to an ecological balance.
An ecological balance is when all parameters are also in check within the aquarium and it would be as if they were out in the wild.
With that being said, in the wild, fish may not be able to eat daily based on various circumstances, but because they are comfortable with their surroundings they are more apt to survive.
In an established fish tank, there is also typically more waste in the tank. This can be from live plants or leftover fish food flakes from being overfed.
This will allow your fish to forage throughout the tank and have feedings.
New Tank Syndrome
However, fish do not get this opportunity in a newly established tank. There may not be any waste to nibble on, the parameters may not have been consistent, or you could be dealing with new tank syndrome.
New tank syndrome is when the tank is not ecologically balanced which will lead to the fish being stressed and more apt to pass away if they are not fed consistently.
In terms of not being ecologically balanced, new tank syndrome means that there are not enough good bacteria in the tank, and the nitrogen cycle can be thrown off.
Again, this leads to stressed fish who are reliant on consistent feeding times.
To combat new tank syndrome, you should always set up the new tank before adding fish to the tank.
Never add fish to a tank that was just done the same day. Instead, set up the aquarium for at least three weeks before adding fish to the tank.
This will allow good bacteria to accumulate and water parameters to be set.
By doing this, you will also have fish that are less stressed when being added to their new environment.
Duration of Absence
The most important factor when leaving your fish unattended is how long you will be gone.
If by chance you miss a feeding throughout the day, your fish will be completely fine. However, if you have a family emergency and are gone for 3 days, you could run into some problems.
All species of fish can typically go three days without food, but any longer can lead to starvation depending on what species of fish you have and other factors.
If you are planning to leave on an extended vacation, you will need to prepare your tank to ensure not only the safety of your fish, including being fed but also the cleanliness of your tank.
If you are leaving for a month, you should most definitely replace your old filter with a new one and check your hoses for any kinks to make sure everything runs smoothly while you are gone.
Even if you have a fish-sitter, they may not know the ins and out of your fish tank.
Age and Species of Fish
The species of fish in your tank can contribute to how long they can go without food.
For instance, some fish are herbivores and should be fed more often (if there are no live plants in the tank) because they typically get daily nutrients from plants and algae.
On the contrary, carnivores (such as the common betta fish) can and should be fed less often since this is what they are accustomed to in the wild.
Age is another factor when determining how long your fish can go without food. Fry (baby fish) can not go as long without food as an adult would be able to.
This is because they do not have as much body fat on them and they are not yet accustomed to their surroundings.
On the other hand, older fish do have the necessary body fat to survive a bit longer without being fed.
Since different species feed differently as mentioned above, it goes without saying that different species can go longer without food than others.
Herbivores can not go as long as omnivores or carnivores without food. In the wild, carnivores and omnivores typically hunt more and may go days without a next meal.
The common goldfish is an omnivore and can go a bit longer without food since they are also larger than other counterparts as well.
With that being said, a goldfish can typically go between 8-14 days without food.
Since they are omnivores, they will eat leftover plant matter if there are any available, as well as insects that may land in the tank, brine shrimp, or algae.
On the other hand, a nano fish such as a tetra can only live about a week without food.
That is also only if they were fed religiously for days prior. However, they can go longer if they are in a planted tank.
Again, the smaller fish- the less time you have to feed them before they pass away from starvation.
They have less fat reserve, are constantly on the go, and depend on added food to fulfill their nutritional needs.
Steps to Take if Going on Vacation
If you are knowingly taking a vacation, there are a few things you can do to make sure that your fish survive the period that you are gone.
These things include adding an automatic feeder to your tank, adding a food block to the tank, making sure your tank is clean, and getting a fish-sitter if needed (usually for a longer period of time).
Automatic feeders can be found at local pet stores or ordered online and are a great way to ensure that your fish have a food source while you are gone.
Typically, you would add your fish’s food to the barrel of the feeder and then program it to when you would like your fish to be fed.
The barrel will then rotate during those times to disperse food into the tank. These can usually fit up to 6 weeks of food depending on how many fish you have.
Add Food Block
As opposed to an automatic feeder, a large food block can be added to the bottom of your tank.
This holds the same nutritional value as your typical fish food flakes, but instead of relying on a system to feed you fish, they can swim up to the block and nibble on it when they get hungry.
Of course, the larger the block, the longer you have until you would need to feed them manually.
Clean Your Fish Tank
As mentioned prior, you will want to make sure your tank is cleaned before leaving for an extended period of time.
This will reduce an algae buildup and keep parameters in check while you are gone.
Hire a Sitter if Needed
If you will be gone for a month or longer, it is recommended to hire a sitter to check in on your fish sparingly.
This will make it easier to notice if there are any problems with the fish tank and they can also feed them as opposed to relying on other methods.