I need help! I think one of fish already might not make it since a small part of his stomach or something seem to be ruptured. (All pics will be attached). So basically, I found one of my neon tetras with a bulge on the side of his stomach and that must've happened today because I am pretty sure he was not like that yesterday. So I quarantined him with an albino Cory who has a messed up mouth and has not healed. This two are independent illnesses. So I did some research and found out its dropsy and it might be too late for the little guy. But I am worried for the rest of my tank. I removed the Tetra and fed him a little bit of flakes (It is top fin so I don't know if this counts as high quality but they do not like omega). Regardless I didn't feed my fish today so i gave him some and he eats in very small amounts but he still is active and interested in food. He hasn't lost color or anything as well. What worried me was that I had 5 tetras total, 2 died mysteriously, I assume it was the Betta who got aggresive since they had missing eyes and only one had that before, But apart from that they didnt want to eat flakes anymore but rather these shrimp pellets I have for my albino corys. So now I feel like maybe the other tetras may be affected by whatever underlying illness and I don't know whether I should quarantine them or leave them in my main tank. After removing my tetra I did a 50% water change and in the QT tank I added General cure, since my albino seemed to have had a sunken stomach (probably from not being able to eat as much because of his injured mouth). Now Im worrried for my main tank and I dont know if I should treat them all with anti fungal stuff, I added some aquarium salt since I heard it helps as a laxative. I think its too late for the one tetra but I need advice on what to do with my main tank and what medicines to use! Ill talk to a fish vet tomrrow as well. I also will add pictures of my other fish because I think I am bad at spotting illnesses and many of you are very good. So I would like to know if any of them are bloated or have weird spots and clamped fins. On a side note; The betta's scales came off because I think he was trying to squeeze inbetween some dragon stone and the tank wall, he only lost 1-2 scales and I dont think hes pineconing. Thanks for all the help! And i want to know if I should just Euthanize my tetra Tl:dr I have a fish with dropsy what to do?