Shaun

Hi Zac, It is hard to see the tail clearly enough to give you any feedback. I would probably dim your lights for a few days, and keep and eye on it. Can you contact the seller and find out what they were feeding them and the water parameters they were living in? This might help them transition to your aquarium.

Hi, It looks like it could be a fungal infection so have linked a coop article on what they are and how to treat. It also looks like there might be some pineconing going on too? https://www.aquariumcoop.com/en-au/blogs/aquarium/fish-fungus

Sorry to hear your betta is not recovering. From your post you have tried a number of recommended things to try and help. Is it possible to keep the water level low so he doesn't have to swim so far to the surface? This might help him live in a bit more comfort.

Hi Betsy - thanks for checking in! He still has what looks like a swollen chest but is otherwise acting normal. He seems healthy and is swimming about, even building a bubble nest, which he never did in the community tank - presume the flow was too high. I'll probably keep him in the qt tank for another week and see how he goes.

No I don't think so. The scales around the bulge seem stretched but not pineconing. He's in a separate tank now with Epsom salt. Seems to be acting normal other than still enlarged. (images are upside down given how I was holding my phone!)

Thanks for the link - just added half a pea as per the link and he ate it hurriedly! Saw another post about the same thing in a betta and they suggested meds and salt. I am in Australia so we have very few meds so am setting up an quarantine tank and will add salt and see how he progresses.

Thanks Betsy - two days without food and still in isolation. His chest looks to be smaller than it was but still noticeably swollen. I think I'll try the pea and see if that helps. Regarding the heat, I think the heater is on the blink. The light comes on to say it is heating and it is set to 78 but thermometer measures 70. I bought a new heater today so will swap it out and see how it goes.

I have a male Betta living in a community tank that has a really swollen chest. It looks like he has swollowed a marble. Only noticed today. Tank is 20 gallons, heavily planted with 8 cherry barbs, 8 silver tip tetras and four siamese flying fox. Nitrates - 30ppm PH - 7.4 KH - 3 GH - 6 Ammonia and nitrite at zero. Temp is 70 degrees. Last water changes was 4 days ago and no other recent changes to the tank. The betta has been in the tank for almost a year with no issues. For the last week, the tank has been fed baby brine shrimp, frozen brine, frozen daphnia and frozen blood worms. Baby brine in the morning and a frozen cube in the afternoon. I suspect bloating of some kind and have put him in a hang on isolation tank. Any suggestions on treatment? Thanks, Shaun