Top 6 Reasons Betta Fish Die and How to Prevent It
When Betta Fish Die Young
Betta fish are among the most popular freshwater tropical fish out there, and it’s easy to see why. They’re beautiful, with their flowing fins and brilliant colors. They’re mysterious, originating from far-off lands in the East. And, of course, they are very dangerous, having been trained in super-secret fishy fighting styles.
But no aquatic ninja skills can save bettas from the ultimate end that awaits us all. Ashes to ashes; fish flakes to fish flakes. One minute you’re swimming merrily along, the next you’re belly-up and stuck to the filter intake.
There is no escaping the Angelfish of Death. Unfortunately, for many betta fish, it all ends far too soon. If you are the keeper of such a fish it can be pretty disheartening when it dies before its time. You begin to wonder what you did wrong, what you may have done differently and if you deserve to keep a fish at all.
I’ve been there, with bettas and other species of fish. All you can do it take an analytical view of your fish-keeping habits and try to puzzle out whether or not you made a key error somewhere along the line. In some cases, you’ve done nothing wrong. Just like other pets, and even people, fish can suffer from congenital issues that shorten their lives.
However, any time you unexpectedly lose a fish it is worth your time to take a look at things and see if you might need to change some of your practices. This article can help with that process. Here I’ve outlined some of the typical reasons betta fish die, and what you can do to avoid them.
Why Did My Betta Fish Die?
Here are some common reasons betta fish die:
- Poor water conditions: Clean water is a must for any fish, especially bettas.
- Low water temperatures: Bettas are tropical fish and need water temps between 75 and 80°F.
- Overfeeding: Excess food can kill your fish.
- Harassment by tank mates: Aggression—both from or directed at a betta—can reduce its lifespan.
- Stress: Many issues can contribute to stress for your betta, including some you may have never imagined.
- Issues beyond your control: Illnesses and hereditary issues can also cut a fish's life short.
Below, I describe these issues in detail and outline some ways to avoid each.
1. Poor Water Conditions
Dirty water is one of the quickest ways to doom any fish tank. And it doesn’t even have to be visibly dirty. Chemicals from decomposing fish waste and uneaten food can contaminate your tank, rendering the water toxic.
Betta fish have a reputation for surviving in harsh environments where most fish would perish. This is because they are anabantids. They have evolved the ability to take gulps of air from above the water when the water itself is polluted and low in oxygen.
Sadly, this is also what makes people think it is okay to keep bettas in bowls and tiny tanks. Sure, he’ll survive for a while. But small volumes of water pollute very quickly, and it won’t be long before he is feeling the negative effects of poor water conditions. Fin rot and other diseases may be the result, as well as a marked increase in stress that will shorten his life.
Here are four things you can do to avoid this situation:
- Choose at least a 5-gallon tank for your betta. This not only means a better living space for your fish, but the tank will be easier to maintain.
- Use a filter. Yes, betta fish need filters in their tanks. Some 5-gallon tanks come with filters. Otherwise, there are nano filters out there to choose from. If you go with a 10-gallon you will have many more options.
- Vacuum the gravel and perform regular water changes. If you suck up the debris and perform a partial water change every other week, your betta’s home will stay much cleaner.
- Test your water. It is impossible to know what's going on in your tank without testing but fortunately this is easy to do at home. I use the It tests for ammonia, nitrates, nitrites, pH and high-range pH and it is very simple to work with. API Freshwater Master Test Kit.
2. Low Temperatures
Some people seem to think bettas are like goldfish, and they’ll do fine in an unheated bowl or tank. This is incorrect. Goldfish require cooler water, but bettas are tropical fish. As such, they require water temperatures between 75 and 80 degrees.
Cool water again means stress, illness and premature death for your betta. Even if it’s warm where you live if the temperature drops at night it will cause the tank water to rapidly cool.
So, what can you do?
- Choose at least a 5-gallon tank. (Yup, it's worth mentioning twice.) Tiny volumes of water cool off very quickly, but five-gallon tanks maintain their temperature a little better, and 10-gallon tanks are better still.
- Use a heater. Like filters, there are nano versions available for 5-gallon tanks, but more options for 10-gallon tanks.
- Monitor the water temperature. Don’t rely on the heater settings. A simple aquarium thermometer will tell you how warm your water is at all times.
All fish need to eat a healthy diet. This means a good-quality flake or pellet and occasional treats. But some well-meaning betta owners go overboard, adding way too much food for one fish to consume. Just like with people, when fish overeat it can lead to illness. Uneaten food can also foul the water, making it toxic for your fish. And, what goes into a fish must come out, so if you are stuffing your betta to the gills, there is bound to be more waste in the tank.
So, what to do?
- Feed your fish once per day and only as much as he will eat in a few minutes. Try to make sure as little food is wasted as possible.
- Consider a fasting day. Skip feeding one day per week.
- Clean the gravel and perform water changes. Set a regular schedule to maintain a healthy tank. This doesn't have to be a major chore, and there are easy ways to do water changes.
4. Harassment by Tank Mates
Betta fish can have tank mates in certain situations. However, you need to be very careful about how you go about it. Certain types of fish may provoke aggression in bettas, particularly other anabantids or fish with flowing fins they may mistake for another male betta.
But there is another side to the story, one you don’t often think about until it’s too late. While bettas have a reputation for aggression and fighting, they are actually fairly small, slow-moving fish. They can be attacked and bullied by larger fish, and smaller fish may nip at their fins. This means perpetual (you guessed it) stress which inevitably leads to a premature (say it with me) death.
So how do we avoid this?
- Have a backup plan. Whenever you have your betta in a community tank setting, you need to have another setup ready to go in case of disaster. This could be something as simple as a temporary one-gallon bowl (with the intent to upgrade him to a 5-gallon tank ASAP). The point is to have a way to get betta out of there if things go wrong.
- Never try to keep your betta fish with tank mates in a tank under 10 gallons. There simply isn’t enough room for everyone to get along.
- Be very selective about which tank mates you choose, and how you introduce your betta. Read Tank Mates for Bettas and Betta Fish in a Community Tank for help.
As we have seen, bettas can die from poor water conditions, overfeeding, cool water temperatures, and a dangerous living situation. Aside from the physical damage these issues can cause, when your fish is under constant stress, he is more likely to get sick, and more likely to die.
But there are other potential stressors in you tank, ones you may never have thought of. The current from the filter or bubbler may push betta around. He may see his reflection in the tank glass and think it’s another fish, and constantly be looking to fight with himself. If he has no hiding spot such as a small cave or decoration, he may feel vulnerable. If some knucklehead in your household is constantly tapping on the glass, it may scare him.
There are a few simple things you can do here (aside from tackling the person who keeps tapping on the glass):
- Choose a low-flow filter that doesn’t blow him around the tank. Avoid bubblers in small tanks.
- Make sure he has somewhere to hide and escape from the world if he feels the need. Something as simple as a decoration or rock cave is fine.
- Adjust the light in the room so he doesn’t see himself. A little flaring is no big deal, but if he thinks he has to continuously defend himself, it will wear him out.
6. Issues Beyond Your Control
Betta fish are bred in huge numbers. They live in teeny cups for part of their lives, until you bring them home. If I’m saying a tank smaller than 5 gallons pollutes quickly, you can imagine how bad those little cups must be. It seems the deck is stacked against these poor fish from birth.
You have no way of knowing if your fish is sick when you bring him home. You have no way of knowing if he has some congenital issue that he’s going to die from no matter what you do. You can take a new puppy to the vet to get him checked for such issues, but with a tiny fish there is simply no way to know.
If you feel like you’ve done everything right and your fish dies anyway, go easy on yourself. Yes, it always helps to take a look at your fish-keeping practices and analyze if you could have done something differently. But, remember, it may not be your fault at all.
Likewise, if you’ve done all the wrong things and your betta lived for years and years, don’t assume doing the right thing doesn’t matter. Like people, some fish can live unhealthy lives and survive into old age. And some can live in healthy, heated, safe, happy water and die young anyway. All we can do is what we can do. The rest is luck.
Frequently Asked Questions
Can I use tap water to fill my betta's tank?
Probably. It is smart to have your tap water tested so you know exactly what is in there. I advocate using as few chemicals in your fish tank as possible, and you may be able to use water straight from your tap without any alterations. (I do.) This is especially possible if your water comes from a well or other pure source.
If you rely on a municipal water source it is probably a different story. If your water is safe to drink but contains additives like chlorine you'll need to use a water conditioner that has been approved for treating a betta's water.
Tap water typically contains all the minerals your fish needs, if you remove the chlorine, chloramines, and other heavy metals first. Distilled water, on the other hand, is not ideal because it lacks the minerals fish need to be healthy.
Why does the tail or fins of my betta fish look torn, short, or ragged?
A chewed-up, tattered-looking tail and/or fins is mostly likely caused by fin rot or by a tank mate's nibbling teeth. If your betta starts looking a little worse for wear, you should determine and treat the cause as soon as possible.
Fin rot is a sign that your fish has a bacterial disease. You can avoid it by using good tank management practices, not overfeeding, and keeping the water clean. If it's already too late, you'll need to spruce up your aquarium care strategy immediately.
Clean water is the most important thing here. This means:
- Keeping up with water changes.
- Vacuuming the tank and getting rid of excess waste.
- Testing the water to make sure it is safe and remains so.
You may also dose your tank with aquarium salt (not marine salt) to help stave off the infection. I prefer to use aquarium salt on a case-by-case basis rather than having it in the tank all the time.
If the damage is caused by a tank mate's nibbling teeth, it's time to move your betta its own tank or a safer situation.
How can I keep my betta fish alive for as long as possible?
By controlling your betta's environment and making sure he has exactly what he needs, you can lengthen and improve his quality of life. Here are some links to articles that will help you set your tank up:
What is the best kind of food to feed my betta?
Betta fish are carnivores, so their diet should be mainly protein. Appropriate foods include:
- pellets designed especially for bettas
- fish flakes (some bettas won't eat this, though)
- bloodworms (frozen, freeze-dried, or live)
- brine shrimp (frozen, freeze-dried, or live)
- Daphnia (water fleas)
I advise feeding flakes or pellets as the staple of your betta's diet and offering other foods only as occasional treats.
How should I feed my betta?
Feed your fish only what it can eat in about two minutes, and only feed it once or twice a day. Any more and you'll have too much waste build-up in your tank and possibly a sick fish—and neither of these conditions is optimal for long life.
If you are concerned that you are accidentally overfeeding your betta it is perfectly okay to add a fasting day to his feeding schedule once per week.
Note: The container the fish's food comes in might recommend that you feed more frequently, but that’s up to you. The key is to give your betta the proper nutrition he needs without overfeeding.
Caring for a fish properly can go a long way toward making sure he lives a long and happy life. As their stewards, we owe it to them to try our best and keep their interests in mind. We have a responsibility when we take a living thing into our home and care for it. If we aren’t going to take it seriously, why have a fish at all?
Aside from practicing smart aquarium management habits, one other thing you can do is be wise where you purchase your fish. Conscientious pet stores only stock as many fish as they know they can sell in a reasonable amount of time. If you see a massive pile of betta cups filled with dazed and half-dead fish, don’t bother looking for the one healthy fish in the pile. Go somewhere else.
If you’ve lost a betta, it can be frustrating and heartbreaking. You may have made some errors, things you can do differently next time. Being a good betta owner doesn’t mean you are always perfect, but it does mean you do your best and learn from your mistakes.
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
Questions & Answers
Can there ever be too many decorations in a betta tank?
Yes, it is certainly possible to overdo it. When decorating your tank try to strike a balance between choosing items that look good to you, and those that meet the needs of your fish.
Your betta needs room to swim around, and he needs clear access to the water surface. Consider including plants, live or artificial, as bettas sometimes will rest on their leaves. Provide a cave or decoration for shelter in case your betta decides he needs a secure place to hide.
Remember that every decoration takes away some tank space. If you include too many, your betta may feel stressed and crowded, just as if he were in a tank that was too small. A tank that’s overcrowded with decorations will also be harder to clean and allow more places for waste to get trapped.Helpful 62
What if I accidentally changed all my betta fish's water instead of 50%?
If you’ve made an error and changed all of the water in your tank instead of doing a partial water change it’s not the end of the world. There are a few things you can do to help yourself and your fish.
The problem with complete water changes is you are potentially killing off many of the helpful microbes that live in your tank. You are also stressing your fish, who had become accustomed to the water he’d been living in.
Water parameters will swing widely after a full water change, and that’s not good for your betta. A partial water change ensures your microbe colonies stay intact and that your betta doesn’t suffer unnecessarily stress.
Your tank will eventually come back to normal, and hopefully your betta has not been harmed. The concern is for the water quality while this is happening. In a properly functioning (cycled) tank there is equilibrium between the waste your betta makes and the microbes that handle that waste. By performing a full water change you’ve potentially sent that process into disarray.
As a result, waste chemicals may rise to levels that can harm your fish. The only way to know for sure if this is happening is to test your water and get readings for ammonia, nitrite and nitrate. You want your ammonia and nitrite at zero, and your nitrate under 20 or 30 ppm (some fish keepers are fine with nitrates as high as 50).
Test every day, and if you are seeing higher numbers change a small amount of the water (~20%) without bothering the filter or substrate. The idea is to dilute those waste chemicals until your tank cycles back around.
Hopefully your tests will show you’ve not done much damage and things will come back to normal fairly quickly. Then, stick with partial water changes.Helpful 52
Why do betta fish get dropsy?
Dropsy in betta fish is typically caused by overfeeding, feeding inappropriate foods, and poor tank conditions. Dropsy is not a disease in itself, but a symptom of a bacterial infection and the resulting kidney problems. Because the kidneys are not operating correctly, the fish will retain water, and we see the bloating and pinecone-like scales we associate with dropsy.
While any fish can potentially become infected, stress caused by the aforementioned overfeeding and poor water conditions can make a fish more susceptible. Strong, healthy fish have immune systems that can better deal with infections, where fish weakened by poor diets and bad water will fall ill.
Therefore, the most important things in avoiding dropsy for your betta fish are to avoid overfeeding and to keep the water clean. These two steps, if done properly, can help you avoid many diseases and conditions that lead to a premature death for aquarium fish. This means following a proper feeding schedule – perhaps including a fasting day week – and performing regular tank maintenance such as changing the water and vacuuming the gravel.
If your betta fish does show signs of dropsy, the outlook is not good. However, there are some actions you can take if symptoms are recent and relatively mild, such as performing a water change and administering an antibiotic. If your betta lives with other fish you may wish to quarantine him, as the same issue that led to his illness may make them sick as well.
Finally, if you do lose a fish to dropsy and are convinced you did nothing wrong, remember that, just like people, some fish are naturally weaker and more prone to getting sick. It may have been simple bad luck, and no fault of your own.Helpful 42
Which type of aquarium is better, glass, acrylic or plastic?
In most cases, I prefer glass aquariums for a few reasons. For one thing, they don’t scratch as easily. Theoretically, this means they ought to keep looking good as the year's pass. They also tend to be less expensive.
Finally, I trust the construction of a well-made glass aquarium a little more than I do an acrylic tank. This is especially true for large tanks, which may need to hold up over the years without looking dull or, worse, leaking.
However, acrylic does have some advantages. Acrylic tanks are lighter, and they are available in some interesting shapes and configurations that are tough to achieve with glass.
When it comes to small tanks around 5 gallons, I think acrylic options are often a good choice. There are many acrylic aquariums on the market that come with everything you need to start up your tank.
If you are new to fish keeping, or if you don’t want to spend a lot of time hunting down accessories, they’re simply more comfortable to work with than a traditional glass tank.
So, for the person who wants an aquarium 10-gallons or larger which they intend to keep running for years, I recommend considering a glass tank.
For someone who wants a small, attractive, easy-to-deal-with 5-gallon tank for a betta fish (for example) I think acrylic is fine.Helpful 40
Are betta fish good tankmates for mollies?
As with any potential betta tankmate, the answer is a definite maybe. Betta can be great community fish under certain circumstances. The problem is you can never really know how your betta will get along with any other fish until they are put together.
However, mollies certainly would not be among my top choices for tankmates. Mollies are active fish that may provoke aggression in bettas. Varieties such as sailfins and lyretails may be similar enough to your betta in appearance that he mistakes them for another male betta. There is also the chance that a molly would pick on the betta and nip at his fins.
Of course, there is the possibility that they will get along fine, too. Some bettas are more aggressive, where others are more docile. I’ve had mollies that were the terrors of the tank, and others that were peaceful. You just never know.
I would consider other options, but if you do decide to keep your betta with mollies, or any fish as a tankmate, make sure you have a backup plan in case things go wrong. You’ll also want to make sure you have a large enough tank, ideally bigger than ten gallons.Helpful 38