comments:
You also need to treat the water with beneficial bacteria. https://a.co/d/0gMI5hYKFritz zyme 7. It naturally and instantly removes ammonia and nitrites. You are shocking the fish with each water change too. Especially if you’re not conditioning the water enough. Or the temperature is different etc. You won’t know unless you have a water testing kit if you’re actually conditioning the water and making it safe. Sometimes up to 5 times the amount of conditioner is needed in some cases to dechlorinate tap water. Maybe find out what your neighbor was using for the water changes, because it sounds like the fish was doing fine with the neighbor. Although in a small tank, it must have been stable. Also, the water you want to use for water changes needs to be treated and aired and temp balanced for at least a couple hours (24 hours is ideal) before using with your fish, especially when a fish is in a critical state. You can still save this fish. But you need to work quickly getting the things you need. The bacteria I recommended stabilizes a tank instantly. You’ll see your fish perk up. The fish doesn’t look to have an infection. To me it just looks shocked and swim bladder but the swim bladder issue is directly related to not having the right good bacteria in the water. Get the fritz zyme. Don’t wait for it to be delivered. Drive to find it. You want to get ahead of this, the longer the fish stays like this. The harder for it to come back from it.