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Hi, this is my betta fish, Aahan. I got him from pet shop on August 6th, 2019. He has no eating nor pooping problems, he is very active.

I’m noticing some change in his fins, namely wrinkled fin edges. I placed him in a 3 liters bowl, where I change the water every 4-5 day and I feed him blood worms twice a day in the morning and evening. He only eats bloodworms and doesn’t like pellets.

Please tell me, what could exactly be wrong with his fins? Any advice would be greatly appreciated.

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    what does your water test show ammonia-nitrite-ph-nitrate.please tell more about your setup filtration-heating,a 3liter tank is way too small for any fish you need to have a tank that is 10 liters as a minimum.what amount of water do you change each time you do the changes. Sep 18, 2019 at 4:58
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    Is your tank cycled? Do you change all the water, or only partially?
    – virolino
    Sep 18, 2019 at 5:34
  • I change 100%water 4-5 days once ....I am a college student and have fish in my hostel room....I have no filter....I haven’t done any water test n I don’t know anything about it...is my fish in bad condition? Sep 18, 2019 at 6:58
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    A fish bowl with no filtration is never really an acceptable place for a fish. Some hardier ones may adjust to it but this is likely to dramatically reduce the life span of your fish.
    – Henders
    Sep 18, 2019 at 8:11
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    As a new (and obviously not well informed) fish owner, the most important thing is to learn about the ammonium and nitrite cycle of an aquarium. Please also have a look at related questions that might help you learn what you need to care for your fish: How does one effectively “cycle” an aquarium?, New tank issue, Will pets stores test my aquarium water?, Nitrogen cycle for new fish tank
    – Elmy
    Sep 18, 2019 at 12:06

3 Answers 3


The picture is great but unfortunately we can’t say for sure how to help your fish.

The raggedy fins aren’t a healthy sign but the good news is that they don’t look irreparable. As soon as you treat the cause, the fins should grow back. If your fish is swimming about and eating, then it’s likely they’ll get better as soon as you remove the cause of their symptoms. I’ll list some things to try here. Sorry if it gets long!

First, as others have said, the bowl is really quite small. A slightly bigger tank with a filter would save you some effort and your fish (Aahan?) some stress. You’re changing the water often, which is good (and necessary) because it means that your fish isn’t swimming in his own toilet. The trouble is that it is a single big change (temperature, chemistry) all at once. Fish don’t respond well to that. It’s stressful for them and stress can cause raggedy fins. A tank with a filter could go, say 2 weeks and then you’d only change 20% of the water (not all of it). That means much smaller changes, less often. It also means less fish handling/nets. Less change = less stress for the fish and less stress for you!

Frankly, I’m far too lazy to ever keep fish in a bowl. A biological filter makes everything far easier and it’s better for the fish.

I’d say that you should also check ammonia, nitrates, pH etc. You should be able to get kits to do this from your local fish shop. BUT you’re changing the water very often and these fluctuations are going to affect the results. You might test just before a water change and see high levels of ammonia which disappear after you change the water. The kits, at best, would let you know your tap water quality and if you should add coral gravel or something to adjust the pH. You could take a sample to your fish shop and they might test it for you.

If you really cannot get a bigger tank with a filter for your fish (and you really should!), then I’d recommend a few things that might make it easier for the fish:

  • get a water conditioner (one that makes the tap water safe for your fish)

  • try leaving the "fresh" (conditioned) water next to the bowl for a while before transferring the fish or doing the change. Equalise temperatures.

  • minimise netting. Use a ladle if you can. Fish hate nets. Don’t "pour" the fish about either.

The blood worms are a decent food. Make sure you’re only giving what gets eaten or the bowl will get dirty quickly. Even then, better slightly hungry and clean than overfed and dirty.

Good luck!


Blood worms are a treat, not a food, it doesn't have most of what a betta needs, try getting better quality pellets and soaking them in tank water first. Mine only eats soaked pellets

Bettas need at least 2 gallons of heated and filtered water, a bowl isn't acceptable at all because it can't be heated or filtered. Bettas nip when bored or anxious and a bowl doesn't provide mental stimulation or decent hiding spots

Changing all of the water ruins the chance of ever getting a cycle

Edit: Please do research on any animal you plan to buy and don't impulse buy it, especially a fish. They're still animals the deserve at least the minimal care


This is definitely fin rot! Happens easily in unfiltered water, which a fish should never be in. Not to make you feel bad, I kept them in unfiltered bowls too until I learned how unhealthy it is for the fish. It is reversible with antibiotics, the one I’ve used is called kanaplex (kanamycin) and works just fine. You can either mix it into the water or their food.

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