20 Reasons Why Your Guppies Are Dying

It is a really sad thing when one or many of your guppy fishes die. But we have to accept it as it is the natural way of things. On the other hand, it will be great if there is some way to know the cause of their deaths, right? In that way, we can know how to prevent these deaths as well as enrich the lives of our guppies.

Guppies die for a number of reasons. The most common reason is a poor tank set up. This means that there is something with the water quality, temperature, and other processes. They can also die due to disease and improper feeding. Further, they can die due to having poor genetics.

There are more reasons as to why your guppies are dying and we will discuss all of those in this article. More than that, as you are now equipped with the knowledge behind the cause of their deaths, you are now more prepared in dealing with issues.

So if you want your guppies to have a good life in your aquarium, then stick around and keep on reading!

Reasons Why Your Guppies Are Dying

Let us dive right into it and start discussing the different reasons. Just remember to not stress yourself too much when you cannot find the reason behind your guppy’s death. Surely, he enjoyed his time in your aquarium no matter how short or long his life was.

1. Poor Water Quality

Not a lot of people are aware that using tap water for the aquarium of your guppies are actually bad. The reason behind this is that tap water has chlorine. Therefore, you should treat the water first before putting your guppies in the aquarium.

The temperature of the water is also important. If the water is too cold or too warm, it can stress out your guppies. Moreover, as time goes on, your guppies will surely poop and pee in their aquarium and these pollute the water.

When there is a waste buildup in the water, it can be difficult for your guppies to breathe as there is no abundance of oxygen. The effect is that they will become intoxicated and they will eventually die.

2. Tank Is Not Cycled

Adjusting the water quality of your aquarium does not simply stop with treating the water as you also need to cycle the water in the tank.

This simply means that the water should have beneficial bacteria as well as the right chemical levels so that your guppies can easily adjust in their new environment.

This is actually one of the most common reasons as to why your guppies seem fine a week after they were placed in the aquarium, but then they immediately die after two weeks. More often than not, a non-cycled aquarium is the culprit.

The water might just be too clean or it did not have the beneficial bacteria for your guppies to survive. A lot of people skip this step as it takes one to two weeks to finish the cycling process. But now you know, doing this step is crucial if you want your guppies to stay alive.

3. Dangerous Levels Of Ammonia

Ammonia develops in the aquarium due to the waste in the water as well as the other natural processes that are present in the tank (dying plant, wrong cycling process, etc.)

It is important to note that there should no ammonia present in your aquarium as it is extremely dangerous to your guppies.

When there is a high presence of ammonia, it can cause your guppies to instantly die. On the other hand, if there are trace amounts of ammonia, your guppies will have a slow and painful death (yikes!). First, they will get ammonia burns, and then they will die.

4. Overfeeding

It is so fun to feed your guppies and watch them eat, right? But keep in mind that overfeeding them is dangerous. For adult guppies, they should only be fed once a day or every other day. Just like humans, when they get too much food, it can affect their health negatively.

Also, overfeeding them can lead to uneaten food which will then turn into waste that can pollute the water. Keep in mind that you should only feed your guppies the amount of food that they can completely consume within 30 seconds.

5. Overcrowding The Fish Tank

It is common knowledge that guppies reproduce like crazy! In fact, your female guppy may give birth to 20-120 guppies in just a month. Therefore, the tank can get overcrowded easily.

There will be more competition for space, hiding spaces, oxygen, and food. All of which can put stress on your guppies.

6. Water Temperature

Guppies hate the cold since they are tropical fish. So make sure that the water temperature is maintained between 72-82 °F. They can actually survive in temperatures of 64 °F and below, but there is a high risk of getting diseases.

The same goes for warm water. Once the water heats up, it will be hard to get oxygen, thus you are suffocating your guppies to death. So it is better to keep the water temperature at the levels we mentioned above.

7. Poor Genetics

For this one, you really do not have much control as your guppy’s mortality rate is deeply embedded in their genes. Some guppies simply have stronger genes than others.

Usually, when you buy guppies from big pet stores, they have bad genetics which results in guppy death in just six to seven months. But if you purchase from guppy breeders, they can live for a long time.

8. Parasites And Diseases

The chances of your guppies getting diseases are influenced by a number of things. It can be a mixture of bad genetics and poor tank condition. Surely, when your guppy’s immune system is down, he is more likely to get sick.

Some of the common diseases are ick, velvet, flukes, and fin rot. Good thing is, these diseases can be treated. However, if it is paired with bad water conditions and poor maintenance, these simple diseases can lead to their death.

There are also some diseases that cannot be treated like guppy tuberculosis. If your guppy has this, then it is highly likely that he will die, so you should separate him immediately so as not to affect your other guppies.

9. Injury

There are just those times when your guppies get into serious trouble. First off is the fact that there might be bullying inside their tank and they can get into a fight with one or more guppies.

This will lead the “defeated guppy” to become injured which will then make it hard for him to hide or forage for food.

Another possibility is that your guppy accidentally got sucked in the pump or filter. Guppies are very inquisitive and even if the filter is like a piece of roaring machinery to them, some will still manage to check it out which leads to irreparable injury.

10. Stress

Guppies can get easily stressed. It can stem from too much competition, mating season, or they simply do not get along well with their tankmates. But can stress cause death?

Unfortunately, in the world of guppies, it does. Stress leads them to not have an appetite and just keep to themselves. In short, it can lead to death due to starvation.

Moreover, a stressed guppy can go on for days without sleeping which contributes to lethargy and immediately after—death.

11. Mixing Incompatible Fish

If you are planning to have a community tank, be sure to put fishes that are compatible with each other. A good starting point is to put fishes of the same size. Compatible fishes with guppies are:

• Corydoras Catfish
• Platy Fish
• Molly
• Tetra

Always do your research first before you add a different fish as they might be incompatible. Like in the case of mixing guppies and betta fishes. Well, that will just result in a whole lot of guppy fish death.

12. Birth-Related Death

This is in line with your female guppies dying. The good news is the percentage of this happening is just 5% However, it does happen.

We mentioned earlier that female guppies give birth a lot and birth-related deaths happen usually when the female gives birth for the 6th time or even more. Their bodies just cannot take the “mating ritual” anymore, more so the live birth.

13. New Tank Syndrome

New Tank Syndrome is the term used by fish breeders and owners who experience fish death due to unforeseen circumstances. There is still a lot of research happening behind this syndrome, but a lot of people have theorized that this is due to the shock.

No matter how well you tried to treat and cycle the water inside your tank, your guppies were just so shocked in their new environment that it led to their deaths. There is nothing you can do about this really, but just hope that most of your guppies survive.

14. Wrong Aquarium Setup

Of course, you should set up your aquarium based on the needs of your guppies. Sometimes, we get carried away with the aesthetics that we place a wrong plant or a wrong substrate for our guppies which is not good for them.

There are even cases where a lot of guppies die because there are not enough plants and other hiding places like caves. So you never know what type of environment your guppies will prefer. You better stick with the basics first, then add accessories as you see fit.

15. Lack Of Maintenance

One cannot really keep guppies or any fish at that without doing proper maintenance. Even though you have the best pump and filter, or even the best lights, you should not just leave them be.

There are still those times when you need to get your hands dirty and clean these apparatuses. More than that, you should also do water changes based on the situation inside the tank.

Obviously, when the tank is poorly maintained, your guppies will find it hard to survive in the murky waters.

You should also read this article: Can guppies survive without a filter?

16. Rapid Water Change

This is in relation to the water changes we mentioned before. Of course, while you are cleaning their water tank, you will transfer your guppies in another temporary container. The change in water temperature can stress them out.

Also, when you put them back in their main tank, they may also get stressed due to the varying water conditions (even if it was their previous water conditions, guppies can be weird) So the trick is to do frequent but little water changes.

17. Rough Handling Or Travel

In general, guppies are not “hardy” fishes. Therefore, any sort of rough handling can really cause irreparable damage. If you moved into a new place and your guppies experienced rough travel, it is highly likely that some of them will not survive.

The same goes for traveling from the pet store to your home. People from the pet store sometimes rough handle the guppies when catching them to place in a plastic bag, so they get a little beaten up. When they cannot recover, they will eventually die.

18. Old Age

Guppies can live around two to three years when they are cared for properly. For some, they can even reach up to four years! So it is simply natural for your old guppy to die.

You do not have to worry as guppies reproduce fast, so surely your fallen fish friend has a “clone” somewhere in the aquarium.

19. External Factors

These external factors are attributed to the fact that yes, sometimes you can make a mistake too! You might have dropped a harmful chemical in the tank, or your cat suddenly wanted to play with the aquarium, or your guppies went on an adventure on your wooden floor.

All of which are accidental and unforeseen. Therefore, you should not beat yourself up too much. Just do what you can for your guppies.

20. Unexplained Death

After going through this long list of reasons and you still cannot tell the reason behind your guppy’s death, then it is simply an unexplained one. Unlike cats or dogs, fishes cannot really signal us if there is something wrong.

Even though you did your best in maintaining the conditions of the tank and you are on top of caring for sick guppies, sometimes, they still manage to die.

Again, this is just the natural course of things and you should not be too worried about it just as long as you know that you are doing your part.