Reasons Betta Fish Die

There’s nothing more disheartening than bringing home a Betta and having it turn belly up within a few days. This is even more devastating when there’s a child involved and you have to explain to them that their new pet has made the trip “across the rainbow bridge.”

Even though there are circumstances beyond our control that may lead to the death of a Betta, the good news is, most of the time, the demise of this species is preventable.

Let’s explore the reasons Betta fish die and how we can avoid them or deal with the causes if they should occur. 

betta fish


Reason #1 – Rough Travel/Breeder/Retailer

Unless you have a breeder of Betta in your area, these fish have to travel (sometimes) long distances to get to the pet retailer or your home (if ordered online). This can lead to stress on the fish (temperature changes, being jostled around), which can weaken the fish’s immune system. 

When your Betta has a weakened immunity it leaves him open to disease which could lead to death.

If you cannot get the Betta directly from a breeder, then be sure to ask the pet store when the fish came in to ensure they have had enough time to develop any issues before you make the purchase and become attached to him. 

Reason #2 – Not Acclimated to New Habitat

Never bring home a new Betta (or any fish) and just pour him into the tank. This is a common occurrence for first-time Betta owners and it can be fatal to your fish. This is because the temperature, pH level, nitrates, and nitrite levels will be very different from a travel cup or bag to what is in your home aquarium. 

The best way to acclimate your Betta is to begin by floating the cup or bag inside your aquarium. Do this for at least 15 minutes, so the water temperature inside the travel container can become the same as inside the tank. 

Next, you will want to slowly add your tank water to the travel container. If your Betta is in a cup, add a tablespoon of tank water to the cup every 15 minutes for 45 minutes. If your Betta is in a bag, then you can add about ΒΌ cup of water to the bag for the same length of time.

Once the 45 minutes is up, gently scoop your Betta out of the container (using a fishnet) and release him into his new habitat. DO NOT pour any of the old water into your tank. This can be harboring bacteria or parasites.

Reason #3 – Did Not Treat the Tap Water

Tap water contains chlorine which, although makes it safe for us to drink, can be a fast killer to the fish species. Before you add a Betta to a new aquarium, be sure to use a product that will remove chlorine (and other harmful chemicals) from the tap water. This is also important to remember when you are doing weekly water changes. 

Reason #4 – Uncycled Tank

Cycling a fish tank means it has had time to create the beneficial bacteria inside the environment to help support the life of your Betta. Putting a Betta into a “fresh” tank is very tasking on the fish and could lead to its sudden death, especially if it is already compromised. 

Naturally cycling a tank can take up to six weeks without any fish – and let’s face it, nobody really wants to wait that long to add their new friend. However, you can add products that contain healthy bacteria to speed up the process. Read the label for manufacturer’s guidelines and details when using these products. 

Reason #5 – Overfeeding

The belly of a Betta is only about the size of its eyeball, so when we dump in a lot of food, this gluttonous creature will eat it all. Unfortunately, full bellies can also lead to bloat and constipation that can lead to death. Only feed your Betta a couple of pellets twice a day, or as much as it can consume in one minute. 

Reason #6 – Lack of Filtration

When pet retailers “hold” Bettas in tiny cups, the uninformed customer may believe that cramped spaces are okay to permanently house this species in. This is not true and may prove to be detrimental to your Betta. 

A good filtration system not only takes out the impurities in the water (like ammonia, nitrates, and nitrites) but also provides much-needed oxygen and a place for beneficial bacteria to grow. 

Reason #7 – Did Not Provide a Heater

Again, “holding” cups send the wrong message. Bettas need warm water (75 to 80 degrees Fahrenheit), so unless the room your fish is housed in is this temperature, you will need a heater to establish the proper environment for the Betta. 

Having a tropical habitat for the Betta allows him proper digestion (too cold inhabits this) and will encourage him to swim and explore. A heater will also turn on and off to keep the preset temp constant (big fluctuations in this can also cause stress and disease in your fish).

Reason #8 – 100% Water Changes

Changing all your Betta’s water is very stressful on the fish and can cause sudden death due to shock. We recommend only performing partial water changes (25%).

Small containers will build up high levels of ammonia and other harmful toxins which can lead to the death of your fish; however, when we completely remove all the old water, we also lose the beneficial bacteria and change the pH levels.

To remedy this situation be sure to use a filtration system in at least a 5-gallon tank. 

Reason #9 – Water is Out of Parameters

If the nitrate, nitrite, ammonia, and pH levels are out of parameters, this can greatly affect the health and well-being of your Betta. Higher and lower levels of “toxins” in your fish habitat can “burn” your Betta scales and fins which can lead to death. 

Keep an eye on the pH and other levels by using a test kit, then correcting them as needed. 

Reason #10 – Parasites & Illness

These are two common reasons why Betta fish die. Parasites and diseases can be introduced to your tank through both new plants and tank mates. That’s why it is vital that you purchase aquarium additions from reputable sources and also quarantine plants and fish for at least two weeks before adding them to your Betta tank

Regular tank maintenance will also help safeguard your Betta from diseases such as velvet and fin and tail rot that may be brought on by poor tank conditions. 

Reason #11 – Polluted Water

Poor water conditions are a killer of Betta fish because of the buildup of toxins such as ammonia and pH imbalances. Diseases and parasites also thrive in polluted water. When your tank is “toxic” it will stress out your fish which lowers their immunity, leaving them vulnerable to all sorts of issues. 

To decrease the risk of polluted water, be sure to include a filtration system, perform regular tank maintenance (using an aquarium vacuum), and do not overfeed your fish. 

Reason #12 – Too Many Tank Mates

A good rule of “fin” is to only have one inch of fish per gallon of water. If your tank has too many occupants it can lead to high levels of ammonia and nitrates – this can quickly kill a Betta and his “friends.”

Second, a crowded tank can stress out your Betta, especially if he leans toward the aggressive side and feels the need to constantly defend his territory. 

Stress is one of the leading causes of premature death in the Betta species, so keep those numbers down in his habitat.

Reason #13 – Aggressive Tank Mates

We know that Bettas can be aggressive toward their own kind but some fish (like Cichlids) can tear apart a Betta very quickly (avoid housing them together). Even some smaller breeds like tetras can be nippy, which can lead to stress on your Betta.

If you plan on adding tank mates to your Betta habitat, do your research to get the best species to peacefully co-habitat in your Betta aquarium. Even those on paper that are said to be fine may turn out to be too much for your Betta. Have a contingency plan in place if this should happen.

Reason #14 – Habitat is Too Small

We have said this many times, but it’s too important to ignore. Betta’s can not and should not have to live in a small cramped container that does not allow for proper filtration, a heater, live plants, and a light. We recommend at least 5-gallons for one Betta. However, bigger is better.

Small containers will build up toxins very quickly which means you will always be cleaning it out (which will then put your Betta at risk for shock from pH and temperature fluctuations, which could lead to an early death). 

There are many beautiful aquariums on the market today that will provide the room your Betta needs to swim, explore, rest, and live life to the fullest. 

Reason #15 – Poor Quality Diet

Just like any other pet, your Betta needs a high-quality diet to thrive. Bad food choices can affect your Betta’s health by lowering his immunity and making him nutritionally compromised, which, of course, can lead to illness and/or early death.

Good food includes a mixture of pellets, flaked food, live, and freeze-dried foods. Remember, Bettas are carnivores so daphnia, mosquito larvae, and brine shrimp are excellent options. 

Reason #16 – Jumped From Tank

You may not know this about the Betta species, but they are excellent jumpers and may take the leap from your tank if there isn’t a lid to keep him inside.

Unfortunately, a long fall to the floor or even a hard “splat” on a table may be enough to cause harm to your pet. And, of course, it goes without saying that if he spends too much time outside the water, he will die. 

Reason #17 – Poor Choice of Decorations

Betta’s fins are very delicate, so we want to be aware of the decorations we use. Those that have sharp edges can rip and tear the fins and scales which can leave your fish open to illness or infection. 

Also, be sure if the decoration has a hole in it that it is large enough for the fish to swim freely through. A stuck fish will become stressed out and could then become sick. You will also want to watch for peeling paint, or paint that may seep into the water. This will pollute the tank and could be toxic.

Lastly, never use sticks, stones, or other material taken from the outdoors as they could have parasites, toxins, or chemicals within them that can poison your pet. 

Reason #18 – Old Age

Depending on the species, Betta fish can live from 2 to 5 years. Like any pet, in the latter years of their life, your Betta could suddenly die. However, there are signs of old age. These include;

  • Fading color
  • Frayed fins (not to be confused with fin and tail rot)
  • Lethargic
  • May “nap” more
  • White dot (not to be confused with Ick which are many dots covering the body)
  • No bubble nests
  • Decreased appetite/Weight loss
  • Decreased eyesight
  • Losing scales
  • Hunched back
  • Rapid breathing
  • Slower

It may be difficult to know exactly how old your Betta is (especially if purchased through a pet store) but getting an approximate age will help you to house the Betta in his senior years). 

Additionally, the symptoms we’ve listed are also very common in many fish diseases, so knowing the difference between old age and a bacterial, parasitic, or fungal illness will help when treating your fish.

Conclusion of Reasons Betta Fish Die

There are several reasons why a Betta fish could suddenly die. However, we can prevent many issues by keeping your fish in a minimum 5-gallon tank with a filter, heater, lit hood, and plenty of live plants. 

We also need to strive to feed our Betta a quality, balanced diet to help support good health and prevent disease. 

Additionally, be aware of the types of decorations used to avoid ripped fins that are a vehicle for infections, and make sure your Betta buddy cannot leap from his habitat.

Good tank maintenance will help keep the impurities to a minimum and will allow the beneficial bacteria to grow. 

Armed with knowledge, perseverance, and dedication, keeping a healthy Betta into old age are our goal and our pleasure.