How Long Can Guppies Survive Without Feeding?

Fish keepers around the world, unite! Today, I’ll talk about a particular subject that interests all of us – how long guppies can survive without food. Many of us find ourselves at odds with our best interests. We want to take care of our guppies but we also want to leave on vacation somewhere for a few days.

But what happens to the fish? If they don’t eat, will they die? How long can they survive without food?

Basically, guppies can survive up to two weeks without food but that’s not everything. Guppy fry, for instance, won’t live more than three days without food. And there are many more things to consider when leaving your guppies alone for a few days. Keep reading because I’m about to dig deep into this topic!

Pre-Departure Aquarium Preparation

Before leaving home, you should check off a few things with your aquarium. You want your guppies to be well and alive when you back home, right? Then, I suggest doing this:

– Do a few filter maintenances for a few days before you leave

Your filter takes care of all the fish waste and debris that piles up in the aquarium. With time, it gets clogged up and stops functioning at full capacity. If you don’t clean it, there’ll be more and more ammonia and nitrates in the water, which endanger your guppies. A sponge filter requires extensive rinsing in a bucket and you’re good to go.

For an internal or a canister filter, though, you’ll need to put in more work. Clean the mechanical filter without touching the biological one. Remove all the piled-up muck and debris, then place the filter back. Before leaving home, clean up your filter once per day, for a few days. This’ll put the filter on a fresh start, with zero filth and debris to endanger your fish.

– Perform one big water change before leaving (50-70% water)

Water changes are the alpha and the omega of fish keeping. Every good fish owner will tell you that doing water changes is vital to keeping your fish safe. Through water changes, you eliminate the accumulated fish waste, nitrates, and ammonia in the water. A 30% water change once per week will usually suffice.

But before you leave, perform a 50-70% water change so you diminish the nitrate levels even more. The toxicity level will go back to minimum levels and it’ll reach dangerous levels much slower. You’re safe to leave home for a few days and not worry about your fish dying on you!

– Put the aquarium lights on a timer

Guppies need artificial lighting if you want them to grow up to be healthy. But when you’re not home, you can’t control their lighting. Or can you? With an automatic timer, you can easily set the lights to turn on and off at desired times. But if you don’t have access to a timer, don’t worry.

You should keep the lights off until you come back. Too much light will keep the guppies awake and they may even die from exhaustion. But they should still receive some level of light, so place the aquarium near a window.

– Make sure there’s no plant matter or dying fish in the aquarium

By now, it should be clear that dead leaves and dead fish in the tank are not good. They’ll turn into nitrates and ammonia, and these things are deadly for fish. Nitrate and ammonia make up the very definition of water pollution in aquarium terms, actually. So, make sure you eliminate dead leaves from the aquarium.

Not only that but check your fish before leaving, as well. Are any of them sick or dying? Remove them from the tank as soon as possible. When they die, fish will substantially boost the ammonia level in the tank.

Ammonia kills more guppies, which release more ammonia when they die. And that’s the beginning of something unpleasant if I’ve ever seen unpleasantness!

What About an Automatic Feeder?

Automatic feeders are quite good if you need your fish well-fed even though you’re not around to feed them. There are plenty of quality-made automatic feeders online, and you can easily find them with a Google search. Personally, I don’t use automatic feeders because they’re not always a good idea. Adult guppies can easily tip the scales into becoming overweight, and I don’t trust automatic food dispensers.

Guppy fry, on the other hand, can’t survive long without food. So, I strongly recommend an automatic feeder for them. The Eheim automatic feeder is a handy tool that will never lead you astray. So far, I’ve had no problems with it, and I even had to leave home for an entire week. When I came back, the fry were well-feed and healthy.

How Often Do Guppy Fry Need to Eat?

Ask anyone and they’ll tell you about the 3-day mark. After three days without food, guppy fry will start becoming sick and even die. An auto-feeder becomes a necessity if you plan on leaving home for more than 3 days. I wouldn’t recommend leaving fry unfed even for one day, if possible. An auto-feeder will offer the necessary sustenance so the fry can survive until you get back.

If you’ve established a microfauna in your aquarium, with algae and seed shrimps, guppy fry won’t have any problem with food. They’ll feast on plants like daphnia, seed shrimps, and they’ll graze on algae all day long. Most often, they won’t need anything else, so an auto-feeder becomes redundant. Though, you should still keep it around just in case.

If you keep your guppies in an outside pond, it’s even better. Your guppy fish will eat larvae, algae, and bugs that will eventually fall into the water. Their food supply is all but accounted for, and you rarely need to feed them, if ever. But chances are you don’t live in a tropical climate, so keeping guppies outside is a far-away dream.


Guppies can survive without food for a couple of weeks but only if their water is in a good condition. That’s why you must perform a big water change and clean the filter before leaving.

If you have guppy fry in the tank, set up an automatic feeder to keep them alive. That’s pretty much it. If you have any questions, leave them down below and I’ll reply shortly!

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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