I don’t know if anyone can help me, but I have a betta who is sick. I thought he had Dropsy, because his sides have become very swollen and his scales started to stick up, but he has been this way for I’d estimate three or four months, and I’ve read that Dropsy usually kills within 15 days. He is in a small aquarium with filter. He has a tendency to lean on the side that is most swollen, but he props himself against ornaments to stay straight. He hasn’t loss color and is still eating. He eats pellets, not live food or flakes. He mostly lays at the bottom, but will still swim up for air. I clean the tank every 1 to 2 weeks. I also add salt to the water. When he first started getting sick, as I said, I thought he had Dropsy so I put Maracyn-Two in the water, but that didn’t help. I’ve also tried raising the water temperature and adding Aquari-Sol to see if that would help with sluggishness, but nothing is working. I’m not sure what else to do. Any advice?

I add aquarium salt, not table salt. I also have a filter and heater in the aquarium. The betta is almost 3-yrs-old, but I’ve read on several reputable betta websites that bettas can live 5 to 6 yrs.
Just to clarify, my betta is in a 3 gallon tank, and I regularly test the water. There isn’t a nitrate/nitrite/ammonia problem.