This is Ringo.

enter image description here

I’ve had him for almost 2 years and he’s been happy until the last week or so. He lives in a 1 gallon (3.8 L) tank (I know it’s small, blame the Petsmart employee who suggested it) and he has a filter and a heater. I change his water at least one time a month, and I clean everything during that time and change the filter. I use tap water with a water conditioner when I change the water and I use a bacteria starter every morning for the next five days after changing. He’s gone through spells where he wouldn’t eat much, but he’s always perked back up; however, lately he’s been laying on the bottom of the tank, either right side up or upside down, or laying in his little submarine house, and he hasn’t been eating at all.

enter image description here

Yesterday I noticed this white-ish sore on his side. Can someone help me please? I just don’t want him to suffer.

Unfortunately Ringo passed away less than 12 hours after I posted this. Yes he was in a small tank but I did do my research and dosed his water with the correct amounts of conditioner, bacteria starters and medications according to the amount of water in the tank. I’ve had a betta fish before in a tiny less than half gallon bowl with no filter or heater in tap water that lived over 4 years. I did what I could with the information I was given and found via petsmart and the internet. The plants were not sharp plastic, they were made of rubber. Nothing in the tank was sharp. I tried my best but unfortunately it wasn’t good enough. I’m sorry to Ringo and thank you to everyone who gave helpful advice.

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    I know this is not a solution, but he is really beautiful. And I am sorry about what is happening to him. I hope he recovers soon.
    – Kakar
    May 26, 2021 at 8:15
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    I did do research and what I read I followed the cleaning directions that I read. No need to be rude. I tried my hardest. And I had a betta fish in a small bowl with no filter or heater with tap water who lived for 4 years and never got sick. I did what I could with the knowledge I was provided on the internet. May 27, 2021 at 18:27
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    @Sixtyfive Please do review the Code of Conduct and refrain from making condescending comments. The OP says that they were cleaning everything in the tank on a monthly basis which is probably why it looks so clean. Also, they explicitly state that they were using water conditioner and I see no reason to doubt that. May 27, 2021 at 19:41
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    @MacyJaimes Sorry to hear about your loss. I've had that happen to me, too and it's definitely difficult. May 27, 2021 at 19:49
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    @EJoshuaS-ReinstateMonica There was no intention of condescension and I do apologize if it came across that way. The fact of the matter is that it looks too clean to be an appropriate environment. By the time the second photo was taken, it would have been time for euthanasia. And yes, people do very often make the mistakes that were made here because of zoo shops who are looking for a 2nd, a 3rd, ... sale. I wish both stopped: selling animals before selling relevant literature and buying animals before reading relevant literature.
    – Sixtyfive
    May 27, 2021 at 21:58

3 Answers 3


It is most important that a betta fish have the right environment. If the environment is right, it's easier to treat any illnesses the fish may develop. Your fish needs at least 5 gallons (19 L) (despite what a pet store employee recommends, you can always get a different tank).

Additionally, the smaller the tank, the more frequently you need to perform water changes. One month is not enough for a 1 gallon tank - you should change the water at least once a week, nearly 100% change. This is why it's important to have a larger tank, too. The larger the tank, the easier it is to maintain a good nitrogen cycle and bacteria. (You shouldn't need a bacteria supplement in the right environment). To make sure your tank is correctly cycled and in a healthy state, check the pH, Nitrates, Nitrites, Ammonia, and water hardness. Knowing these can also help you identify issues (wrong levels can make a Betta very sick).

Potential illnesses: Here are some things I can try to diagnose (keeping in mind I'm not a vet, and only speak from experience keeping Bettas and researching common illnesses)

  • Swim bladder issue: Your fish is laying on its side on the bottom of a tank - this is a good indicator that your fish has a swim bladder issue and is likely struggling to get to the top for air. Overfeeding is a common cause for this. Here is a good guide you should read.
  • Fin rot: It looks like his fins have potentially rotted away (seeing the difference in your two photos). There's a chance that the fin is also simply being torn by aquarium decorations. Check that your decor is not sharp. Fins can grow back in the right environment. Otherwise, check out this guide on fin rot.
  • Missing scales: The white spot you notice on his side looks like missing scales. If there is something sharp, this can tear off scales, just like it could tear his fins. Like fins, scales can grow back. But left untreated and in the wrong environment, can cause a bacterial infection.
  • Dropsy: I can't fully tell, but I see signs of pineconeing (betta bloats and scales stick out more than normal, like a pinecone). This indicates a high likelihood of a bacterial/water quality issue. This could be due to adding so much bacteria starter to a tiny tank (high bio-loads can cause dropsy). This is a great article on identifying and treating dropsy.

Again, it's hard to diagnose a fish with just an image and not knowing the exact water parameters. I've listed a lot of potential issues here, which can feel overwhelming. This is why I always recommend getting the environment right, first. Start there. The best treatment for a lot of the issues I listed is a healthy environment!

Next steps: So you don't shock your little guy, keep it slow and small at first. I would maybe start by increasing your water changes, stopping the bacteria you add, and buying a water testing kit to test your current setup. Consider your 1 gallon a hospital tank, and you can start cycling a larger tank while you treat the current environment.

I hope this helps, and best of luck with Ringo!

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    Would it be better for the bacteria, to not change water and clean the filter & everything in the tank in one step? May 26, 2021 at 5:12
  • @Allerleirauh potentially, but there are clear indicators that the bio-load is too high and should be reduced. I would test the water (pH etc.) first to determine what needs to happen next though. Then maybe do a slower ramp up of water changes (I.e., 50% one day, 75% a few days later...)
    – Gwendolyn
    May 26, 2021 at 14:18
  • The "bioload" is likely not too high, I don't think it's possible for the bioload to be too high and no visible "cloudyness" to be in the water, the cloudiness is the physical bacteria floating in the water. The artificial decor could have played a roll, but the life span of betafish is actually between 2 -> 5 years, it's entirely possible he was already old when they bought the fish.
    – Krupip
    May 26, 2021 at 19:11
  • @hythis This is possible it's not a bioload issue. I only hypothesize this because: Adding bacteria starter at that frequency in such a small space could lead to that, it's hard to tell if the water is cloudy from the image, and the symptoms the fish is showing can all be linked to that issue. Basically, I hoped to just emphasize the importance of a healthy environment.
    – Gwendolyn
    May 26, 2021 at 21:32
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    @hythis Dirty or cloudy water does not always mean excessive bioload, and excessive bioload does not always manifest itself as dirty or cloudy water. Some types of bacteria, whose blooms cause visible cloudiness, are harmless. Excessive bioload means that ammonia and/or nitrite are generated faster than nitrifying bacteria in the filter could metabolize; both ammonia and nitrite are toxic to aquatic life, but they water-soluble and colorless thus invisible without a specialized test.
    – lila
    May 26, 2021 at 22:53

The first thing to check with sick fish is the water quality. As indicated in the excellent answer from Gwendolyn, small tanks need more frequent water changes (even if you're using a pump with a filter). Once a month seems a little infrequent for a tank that size. Personally, for my 1.6 gallon tank, I vacuum the gravel and do a water change of no more than 25% once a week.

Adding that much bacteria starter seems a bit excessive to me, especially for that small of a tank, but I could be wrong. Check the directions to see what the recommendation is for your particular product.

One other thing to consider: what kind of heater are you using? Do you have a digital thermometer? I used to use a 5-watt heater that heated continuously, but I found that the water temperature was fluctuating too much (which is stressful for Betta fish). It's better to have one that measures the water temperature and turns on when it detects the water getting too cold. Ideally target the 79 - 81 °F (26 - 27 °C) range.

Water that's colder than 75 °F (24 °C) can suppress your fish's immune system (leaving it more prone to illness), and large temperature swings causes undue stress. (Excessively warm water is also uncomfortable for the fish and can, in the long run, lead to an excessively high metabolism and premature aging).

In terms of the disease, I'm obviously not a vet, but white spots like this often imply the presence of a bacterial or fungal infection. Bettafix and Pimafix are sometimes used for these purposes. The word of caution is that Melafix, which is a stronger formulation of Bettafix, and Pimafix have the risk of coating their labyrinth organ and causing breathing problems, so be sure to check for that if you use Pimafix in particular. If they frequently rise to the surface and appear to "gasp" for air, this could indicate breathing problems.

Also, believe it or not, aquarium salt is sometimes used. If you go this route, make sure that you use aquarium salt, not table salt (which tends to have additional additives that are geared towards human consumption, such as iodine). Be sure to dissolve it in conditioned water before you add it to the tank, and to add the correct amount for your tank size.

There are a wide variety of other treatments available for bacterial and fungal infections too, even including human antibiotics and anti-fungal medications. I would encourage you to start treatment sooner rather than later, as early treatment can often make a big difference for long-term outcomes.

Make sure that, regardless of what you use, you don't overdose your tank; this is much easier to do with a small tank than with a large tank. Many tablets in particular are geared towards tanks that are 10 gallons or more, so if you got one of those make sure that you subdivide it properly for your tank. (You can get a pill splitter at a drug store for that purpose).


Other people have talked about possible issues presuming the problem is with the tank setup somehow. But you say you've had your Betta fish for 2 years. In all likelihood, it was already a year + old when you bought it; Betta fish live between 2 to 5 years, and probably the most common symptoms of old age are these kinds of problems, where they get bacterial infections and die. As they get older, immune systems and bodily functions break down, they become very vulnerable to infection and are unable to heal themselves effectively. This can happen suddenly.

You may have to look into euthanizing the fish if this is the case.

I don't think this was a "bioload" issue. The most obvious sign of overabundance of bacteria, or "bacterial blooms" is cloudy water, which you don't have. And even in this case, such events are more representative than other issues, than bacteria blooms are actually problems in and of themselves. In the absence of both other organisms and live plants, such problems are unlikely to happen after 2 years, even in a 1 gallon tank with out obvious signs.


I also agree with the other posters, Betta fish should be in 5 gallons (19 L) minimum. But in addition to that, you need to avoid having hard, tough to bend surfaces (like your plastic plants). Even in the event of old age, it still often takes some sort of damaging event to start the initial infection, the Betta fish may have gotten a tiny cut on its fin. You may opt to go for live plants. This requires more setup (which is out of scope for this question), but can produce healthier environments in general.

You may in the future also aim to purchase more "natural" Betta fish, or female Betta fish, which have often have less flamboyant colors, but don't have issues with fins getting cut on décor. These also have less inbreeding issues with natural breeds, which also contributes to early death and disease resistance.


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