5 gallon Betta Tank

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Aquarium Advice Newbie
Jan 19, 2024
I have a 5 gallon Betta tank with 2Neon Tetras, 1 Corydora and one male Beta. One day I noticed one Tetra was missing and couldn't find any evidence of it's body. A few days later, my Corydaora was dead on the bottom of the tank. I still have what appears to be a vey vibrant Neon Tetra but the Betta is not doing well, lies on the bottom, he does eat but kind of looks like he's dying. I want to start over clean out the whole tank. I know I will have to euthanize the Betta but what do i do about the Tetra, could it be carrying a disease?


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Before we go down the euthanasia route lets try and figure out what wrong with the betta before writing him off. Please take a read through the "unhealthy fish" sticky and give as much detail as you are able. If you dont know the answer to a question just say " i dont know" rather than skipping the question.


As for the tetra, the best thing for it is to provide a suitable home. Tetras are social fish and they need to be kept in groups with a tank that is big enough to support a group, giving it enough swimming space. A 5 gallon tank doesnt do that. Living alone or in a pair is going to be very stressful for that tetra. Same goes for corys. A neon tetra needs to be kept in at least a 10g tank and in a group of at least 6 fish. Ideally 20g and at least 10 neons. Most corys should be in 20g + and kept in a similar sized group. Stress causes illness and a poor quality of life, both of which lead to shortened lifespans.
5 gallon tank issues

I have had the 2 tetras, corydora and betta for over a year now, but all of a sudden the one tetra disappeared, then a few days later the 2nd one died and then the next few days the cory died. I did replace ione tetra, who is seeming to do fine. If I want to start fresh, do I want to get rid of the tetra, but still have this questionable Tettra.?


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As said, let's put aside the starting afresh and try and figure out whats wrong by going through the unhealthy fish sticky.

Tetras and corys shouldn't be kept in 5g tanks or in singles or pairs. Them dying could just be down to them living in an unsuitable environment, but them both dying at the same time and the betta also not doing so well might suggest a problem. The betta could just be old, but without anything to go on, its just speculation. Personally, if you cant provide a suitable home for the tetra rehoming it would be appropriate. If you cant find someone to take it then you make the best of a bad situation and try to diagnose the issue and give it the best quality of life you are able.
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About the betta: what do you feed him, and how much? One of mine recently went through the same thing, laying on the bottom a lot and looking like he was dying. Moving occasionally to different spots but lethargic. I thought about his end-times, but then, as Aiken says, about what was wrong before writing him off.

I decided to address constipation (and swim bladder disease) first. Fasting the fish for 24-48 hours is recommended. He'd been indifferent to food for a few days so I quit feeding to see how long before he appeared at our agreed upon feeding spot. It was 24 hours before he showed an interest.

A green pea is used for constipation. Run one under hot water until it defrosts in your fingers; pop it out of the husk. Pinch a tiny bit of it to feed the fish. Now, here's something no one has ever mentioned to me about using the green pea cure: even the smallest chip of pea sinks to the bottom, while the fish floats at the top, getting nothing. On my third try he finally noticed it and dived to the bottom, but still did not find it. On my fifth try (!) I finally figured out how to actually get the pea into the fish: a little spoon, the kind they give sample tastings with at ice cream parlors. I lowered it barely into the water line right in front of him with the pea piece directly going into his lunging mouth. We were both trying here. Success! Literally spoon feeding the fish.

Just that one piece. He gobbled it and I could see he didn't like it. After that, no more food. But 12 hours later - he was his old self! Zipping around, full of life again. I still waited until he was really hungry, begging for food at his usual spot. It was another 24 hours for that.

I feed all my bettas the same, but this is the only one, the glutton who never seemed to get enough, who's ever had a problem. So now he's on a diet: feeding only once a day. The evening meal is out. And only half rations at breakfast. He begs for more, but lesson learned, as he's acting like his youthful self again.

It might be worth trying this simple, basically free test before going the chemical or euthanasia route.
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