Betta Fish has Swim Bladder Disease

My betta fish has been dealing with swim bladder disease for over two weeks. He was doing okay until I had to get rid of an old furniture where the tank was on. The transition was quick since the temperature and about 90% of the water was the same but the acclimation was cut short since he was getting stressed on the cup by trying to jump out. So I let him go into the tank and that's when the problems started. He has trouble swimming normally, is lethargic, and refuses to eat frozen peas, bloodworms, and daphnia.

After about two weeks I decided to start over and move him to a much smaller tank (3.5 gallon tank) but I only added 1 gallon of water that's new and treated. This time I acclimated him for over an hour. I added some Indian almond leaves and only use Bettafix now. After 5 days I tested the water..Ammonia is 0 ppm, pH is between 6.6 - 6.8, and no heater since the tank's temperate is between 78.8F - 80F during the the summer.

At this point, I don't know what to do next. Right now he stays put in one corner of the tank and moves away when I add food in front of him. For months, he's had yellow-golden smudges on his fins but it doesn't look like velvet disease since he's not loosing color, not scratching against objects, and doesn't have dust covering his body.

Pictures and a 1-2 minute video of the fish?
Upload video to YouTube, then copy & paste the link here.
If you use a mobile phone to film the fish, hold the phone horizontally so the footage fills the entire screen and you don't get black bars on each side.

Did you dechlorinate the new water?
Have you tested the tank water for ammonia, nitrite, nitrate and pH?

Moving a fish to a different tank or changing most of the water should not cause any problems, and certainly not swim bladder problems.

What does his poop look like?
Is he eating anything?

Yes, I use API Stress Coat+ to dechlorinate the water. I then wait about 8+ hours before adding it to the tank. I just did a 50% water change. As I was doing a water change, there was a bit of red stuff, which looks like he's now loosing some of his red fins. I've had him on the new tank for about 6 days now. He hasn't pooped since he still ignores all the food I give him. I took a picture of him from above the tank trough the feeding opening but there's no point in taking a video since he doesn't move. He's easily agitated and only swims erratically if there's little movement or sound in the tank. I've tested the water and everything looks normal. The tank's temperature is 80F without a heater.

He mainly stays afloat. Sometimes I see him slowly sinking so he uses his "pectoral" fins to swim up.

if he isn't eating then he's probably dying from an internal problem.
i would euthanise him

There's not a lot of hope there. Swim bladder isn't a disease, but a symptom of unseen diseases, internally. Most are bacterial.
The bladders take their air from the intestines, and if the guts are blocked or infected, they get an unbalanced supply and the fish can't balance.

I'm not sure I would euthanize, but I would be patiently pessimistic. He needs roughage in his diet, as a creature evolved to eat bugs whole, and some people will give a betta a pea to eat. I've never done that, but. It sometimes clears the bowels, if he's still eating. Then you can find a high fibre, bug based food.

GaryE said:

There's not a lot of hope there. Swim bladder isn't a disease, but a symptom of unseen diseases, internally. Most are bacterial.
The bladders take their air from the intestines, and if the guts are blocked or infected, they get an unbalanced supply and the fish can't balance.

I'm not sure I would euthanize, but I would be patiently pessimistic. He needs roughage in his diet, as a creature evolved to eat bugs whole, and some people will give a betta a pea to eat. I've never done that, but. It sometimes clears the bowels, if he's still eating. Then you can find a high fibre, bug based food.

Click to expand...

I decided to use tongs to hold a pea in front of his mouth and he started eating it! I did that for 2-3 days. Today after 14 days he started eating his food! I fed him a bloodworm and some daphnia. But he still has buoyancy issues. As his trying to get closer to the food, he's slowly sinking or is slowly moving backwards. Hopefully he gets better soon...