How Long Can You Leave a Fish at Home For? (The Answer Might Surprise You)

Yes, pet fish are low-maintenance pets. Compared to dogs and cats, a freshwater fish is a walk in the park (not literally, they don’t like that). However, fish are still animals that require care and attention. Quick weekends away and lengthy vacations alike call for reinforcements when it comes to leaving a fish home alone. Food is the biggest factor when determining how long you can leave a fish home alone. Depending on the type of fish, how many fish you own and the size of the tank, you can leave your pet fish alone for two to seven days.

Disclaimer: We’re talking about freshwater fish here! Tropical and saltwater fish have very different needs.

Fish Tank World says most fish can easily go two to four days without food before it becomes a problem. It’s also noted that this isn’t ideal, as it causes stress and knocks the fish out of its daily rhythm, but it’s possible. (Aka, don’t neglect to feed your fish regularly. Save it for vacation time.) After a few days without food, a fish starts burning its reserve energy.

How long a fish can go without eating really depends on its diet, age, size and species. For instance, carnivorous fish who eat worms or bugs may be able to coast after one big meal while plant-eating fish typically need to graze or nibble smaller meals throughout the day to absorb nutrients. Metabolism also plays a role! Young, active fish may need more food to maintain energy, while sedentary or adult fish don’t need to replenish calories as often.

Some species, like Betta fish, can survive up to a week without food. Others, like Angelfish, can make it two weeks. Again, this isn’t recommended and typically only applies to healthy adult fish. But it’s a reminder that a day or two isn’t bad.

A good rule of thumb is changing about 10 percent of an aquarium’s water every week. Smaller tanks or those with lots of fish should have about 25 percent of their water changed each week. The smaller the aquarium, the more often water needs to be changed.

So, a week-long vacation isn’t a cause for concern as long as you do a partial water change ahead of time. Determine how much of the water to change by considering how long you’ll be gone, how many fish are involved and how spacious the tank is. Any longer than a week calls for a pet sitter or friend to stop by and make sure the water quality is good and for a partial change if necessary.

A quick warning! Fish should be monitored after a deep clean and full water change. Don’t do this the night before you leave as you won’t be able to tell if something is off. 

All this is to say leaving your fish alone for the weekend isn’t a problem. Three days is pushing it. More than four, it’s best to invest in a pet sitter who can visit for a feeding. Remember this totally depends on your fish!

If a pet sitter isn’t available, there are several automatic feeders on the market that make it easy to keep your pets satiated without starving or bloating (which can lead to death). Always test a food replacement method before you leave town, especially if you have multiple fish or picky eaters. You want to make sure it works and that your fish will actually eat. 

1. Fish blocks

Time-release food blocks like the Tetra Pond Vacation Food supply your fish with enough food for up to a week. Some fish blocks are gel-based while others dissolve over time. Success typically depends on the size of the tank and whether or not you’ve got a filtration system running.

2. Timed feeders

A more ideal solution may be a programmable timed fish feeder. These can be programmed to feed at intervals throughout the day or even every other day. It’s always wise to test these beforehand to make sure they work.

3. Pet sitter

If a real live person can come feed your fish every other day or so, make sure you tell them explicitly how much your fish should get. Fish food portions aren’t huge and some fish look like they’re begging well past meal time. Overfeeding can lead to bloat, so make sure you let your sitter know what's up.