Are Guppies Hardy? (And What Can Affect Their Health)

If you’re reading this article, then the chances are you’re about to buy some guppies, or you’ve already got some! And you’re wondering, “are guppies hardy?”

Well, keep reading to find out whether guppies are hardy fish and, more importantly, what you can do to make sure they stay happy and healthy, and other great hardy fish that can go in your tank!

Are Guppies Hardy?

Guppies are definitely hardy fish compared to a lot of other fish you can buy for your aquarium. However, don’t make a mistake in thinking that they can handle anything or that they’re the hardiest fish you can buy.

While guppies can survive in most conditions, there are a lot of things that can make them sick and even kill them.

On top of this, a lot of people believe that guppies aren’t as hardy as they used to be. This could be due to poor breeding and genetics, as large pet stores just try to breed and sell them for a profit. Instead of making sure they’re breeding healthy fish.

But make no mistake, if you’re a beginner to the hobby, they’re going to make great starter fish.

What Makes Guppies So Hardy?

Guppies are able to survive in a whole range of conditions quite well. Unlike some fish that need extremely precise conditions, guppies can often survive in a wide range of conditions. (As long as their basic needs are met.)

As well as this, they are also very peaceful fish, which means if you’re keeping them in community tanks with other fish, then they’re not going to be bullied or become the bully themselves, which will keep their stress levels low.

This also helps with their hardy nature.

And lastly, another reason that guppies are considered hardy is their ability to survive in brackish water as well as freshwater. This isn’t common amongst a lot of tropical fish, so when it does happen, it’s impressive.

With that being said, though, there are plenty of things that can make your guppy sick. And if you’re not aware of them, then your guppy isn’t going to be nearly as hardy as you want them to be.

What Can Affect Your Guppies Health?

There are a few things that will affect your guppies’ health and possibly cause them harm and death. However, fortunately, if you’re aware of them, then in most cases, you can stop them from happening in the first place.

Poor Genetics

Unfortunately, if your guppy has poor genetics, then there’s not much you’re going to be able to do. If this is the case, then they may die prematurely. However, you can stop buying them in the first place.

Generally, it’s best to avoid big name pet stores as they normally care more about profit than the well-being and health of their animals. Instead, you should try to buy from well-known local stores that care for their fish.

(Find out how to selectively breed guppies.)

Being Left Alone

Guppies aren’t meant to be solitary fish, and if you keep one on their own, then they are going to become stressed. This means their immune system will be weakened, and they won’t be as hardy as they should be.

The number of guppies you can keep will depend on the size of the tank. However, as a rule of thumb, you should never keep less than 3 guppies in a tank.

(Find out how many guppies you can keep in a 5-gallon, 10 gallon, and 20-gallon tank.)

Did you also know that guppies like to shoal?

The Tank Hasn’t Been Cycled

Another time when your guppies definitely aren’t going to be as hardy as you want them to be is if you’re adding them to a non-cycled tank. When the tank hasn’t been cycled, then the ammonia levels in them can rise rapidly.

If the ammonia becomes too high, then it’s not uncommon for it to kill your guppies or make them seriously sick.

That’s why it’s so important to make sure you’re giving the bacteria in a new tank enough time to grow so that it can deal with the ammonia adequately.

This can take anywhere from 2-4 weeks and sometimes even longer. You can speed up the time by adding fish food to the water and letting it rot. Doing this will naturally increase the number of beneficial bacteria.

You should also be testing the ammonia in the water every day for a few days before adding your guppies. The API Master Test Kit is perfect for this.

(Find out how to set up a guppy tank.)

Poor Water Conditions

While guppies are flexible in the different parameters they can live in, one thing that will make them sick is poor water conditions.

If you’re not cleaning your tank often and making sure that the ammonia levels are low, then the chances of your guppy dying are going to increase dramatically.

Fortunately, though, it’s not hard to make sure the water conditions stay optimal for your guppies. Just change the water every week, vacuum the gravel, remove any food that isn’t eaten and make sure you don’t overstock your tank.

By doing all this, you’re going to help keep your tank conditions good and help your guppies live healthily.

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Make Sure You’re Keeping The Parameters Good

You should also make sure that the pH levels and temperature of the tank are consistently where they need to be to keep your guppies happy.

Ideally, the temperature of the tank should be between 72-82°F. While it is possible for them to survive in conditions much colder than this, it will increase the chances of them becoming sick or suffering from diseases.

As well as that, you should make sure you’re keeping the pH level between 6.8 -7.8. This is the ideal level, and anything over and under this will begin to cause them harm. (Find out how to keep the pH level ideal for guppies.)

Disease And Illness

There are also a few diseases that guppies tend to be prone to, which can make them much less hardy. Fortunately, though, if you’re taking good care of the tank and the water, the chances are they’re not going to suffer from these diseases.

With that being said, here are some of the most common diseases and illnesses that your guppy can suffer from:


One common illness guppies can suffer from is constipation. And unlike in humans, where constipation is only going to be mild discomfort, in guppies, it can actually prove to be fatal.

You can reduce the chance of your guppy suffering from constipation by making sure you’re feeding them good food and keeping the water conditions good.

(Find out more about constipation.)

Swim Bladder Disease

Another illness that can affect your guppies’ ability is swim bladder disease. While the name makes it seem like a disease, in actual fact, it’s actually a name given to a range of different problems that cause the same symptoms in your guppy.

Once again, the chances of your guppy suffering from swim bladder disease increase if you’re keeping them in poor water conditions.

(Find out more about swim bladder disease.)


Guppies will also be susceptible to dropsy when the conditions aren’t adequate. However, it can also happen when they’ve been hurt or they’re old.

Unfortunately, once your guppy is suffering from dropsy, there’s not much you can do to save them, and in some cases, the best thing you’re going to be able to do for them is euthanize them.

(Find out more about dropsy.)

Fin Rot

And lastly, another common disease that guppies can often suffer from is fin rot. Fin rot is when their tails and fins begin to be eaten away.

If you catch it early enough, it’s normally treatable, and your guppies will be able to make a full recovery. However, if it’s left too long, it can often result in body rot and even death.

(Find out more about fin rot.)

What Other Fish Are Hardy?

While guppies are hardy, the general consensus is that in most cases, they’re nowhere near as hardy as they used to be. This is mainly due to inbreeding and poor genetics. However, if you’re not sure about adding guppies to your community tank, here are some other great choices.


Mollies are another hardy fish that look great in your tank. Due to their large size, however, you should avoid putting them in tanks smaller than 15 gallons. They come in a variety of colors, which make them just as beautiful as guppies.

However, you should avoid some species of molly, such as balloon mollies. The fact they look this way makes them vulnerable to sickness and disease.

(However, you can also keep mollies and guppies together.)


Bettas are another GREAT hardy fish if you’re just getting started. In fact, a betta was the first fish I ever owned. While they’re definitely hardy fish, don’t listen to the advice that tells you they can live in vases without filters or heaters.

They definitely need as much care as other fish; however, if you are giving them the right care, then they’re extremely easy to keep alive.

If you want to know more about bettas, then check out Betta Care Fish Guide for ALL the information you need on bettas!

Zebra Danios

Zebra danios’ are some of the hardiest fish you can buy for your fish tank. If you’re an absolute beginner, then these are probably the best fish you can choose.

They’re often used for in-fish tank cycles because they’re able to survive harsh conditions (however, this still isn’t recommended.) So if you’re looking for hardy fish, they’re probably your best bet!


Now you know that generally, guppies are pretty hardy fish. With that being said, they’re definitely not as hardy as they used to be. If you’re looking for hardy fish, then zebra danios are your best bet, although if you’re taking care of your guppies and tank, then they’re going to do just fine.

The most important thing, of course, is to make sure the water conditions in your tank are good and your guppies will be fine!