Please help! My Betta fish has been laying at the bottom of the tank for a while now, and I have no idea why. I’ve tried changing the water to warmer water and cleaned the water. He did fine before but now he’s just changed. He only moves up when I try to get him to move with my finger.(outside of the tank of course.) I have no idea if he’s sick or dying. He doesn’t even go up to get food anymore! The past week I thought he was doing better, he was swimming up but then he just went down again. Please help! I don’t know what to do.

  • 1
    Hi G.P.! Can you provide some details about your tank? Size, filter or no, heater or no, types of decoration, what you add in the water (to remove the harmful chemicals)... etc. etc. If you can, try to check things like the pH and ammonia levels in the tank.
    – Gwendolyn
    Commented Jan 29, 2019 at 0:27
  • It’s a one gallon tank with some other number sorry I forgot. There is a filter (which I change everytime I clean the tank) no heater, some type of plants like one looks like a small leaf while the other is longer. I use a Betta fish clarifier I forgot the name.
    – G.P.
    Commented Jan 29, 2019 at 0:32
  • how old is your fish ?
    – Manuki
    Commented Feb 19, 2019 at 20:36

3 Answers 3


Thanks for providing details! It's hard to say exactly what's wrong with your fish, but I have some suggestions.

I would consider getting a larger fish tank, 5 gallons is the recommended minimum for fish.

Also get a heater. The water in a 1 gallon tank will cool/heat a lot quicker than a larger tank, so even though you added warm water, it would cool down quickly (think about forgetting your mug of tea for an hour after you've just boiled the water).

It sounds like you do a great job with water changes. Remember that the smaller the tank, the more frequently you should do larger water changes (try 50% once a week).

Also, don't change your filter each week, once a month is best (though I've waited up to 3-4 months). The filter will grow good bacteria that is healthy for your fish. So, replacing is each week is also "resetting" that cycle. Instead, rinse the filter out in the water you remove during the water change, and place it back in.

If you can, get some strip tests to test different chemical levels in your water. Strip tests are not as accurate as other tests, but they're affordable and will give you a good idea where you pH, nitrates, nitrites, and so forth are at.

I hope these suggestions help! Bettas are super resilient little dudes, so I hope he gets better soon. :)

  • Some fish are more resilient than others. @Gwendolyn Commented Dec 13, 2022 at 16:26

He may be affected by a disease or dying of old age. Being lethargic and sinking are definitely symptoms that something is wrong, so you are right in searching for advice on this. A fish that ate too much food might behave like yours. He could be constipated also. Maybe the water is too cold or too hot, etc.

What you can do first for a fish that is not feeling so well is to make sure to keep him in very clean water and feed it a strict minimum. Fishes like betta can go several days without eating. The water can be raised by a few degrees without exagerating. Also a small spoon of aquarium salt (not table salt) can help, it will act like a disinfectant. Don't add aquarium salt everyday, it doesn't evaporate, it stays there until you do water changes. Consider checking the ingredients in your fish food and checking online if it'S good or not.

One gallon can be a good tank to try to nurse your fish back to health in controlled water, but for living its life, it is far far far too small and sorry but it might be impossible to establish healthy conditions or good water chemistry long-term for a fish in such a small space. The first step would be to rehome him somewhere suitable like a 10 gallons with substrate and a filter, and cycled water (you could add the water and filter from your 1gal to help start the bacteria population). The small bowl is very likely to be the cause of the lethargy of your fish in my opinion. Also in a bowl shape, some bettas have difficulty to reach the surface, needing to manoeuver a lot.


When my betta got sick, I implemented many of the changes mentioned in Gwendolin’s answer (which I believe were the most effective measures), and I also gave him some medicine.


This is a link to a sort of catch-all medicine that can be used to treat most illnesses in bettas and also as a preventative when introducing new fish to each other. Just be very careful not to overuse this, and also be sure to follow the instructions on the package.

If your betta is not eating, you could also try a variety of food. When my fish was sick, I crushed up the pellets to make it easier for him to eat, and I also introduced blood worms into his diet.

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