Ok, it seems that the more I learn about fish keeping, the more problems that I have. Since re-entering the hobby I have lost one walmart betta (never again will I buy one there), and I am afraid to lose more.
Here's some background: Buddy, my first betta was purchased only after I had spent countless hours researching bettas. A few days after I bought him, I noticed that he had ick. I treated him for that and it went away, but he got fin rot. I tried to treat him for that with melafix, but that did not work and only polluted the water. He ended up dying

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So, that is when I got Flame. He was the only one at the pet store who looked to be somewhat healthy. But I found out later that he has the toughest case of fin rot that I know of. It doesn't bother him and is slow moving, but will not go away. I have tried melafix (with daily water changes this time) maracyn TC, and fungus clear. I gave him some time in between each one, and it is yet to be seen if the fungus clear has worked. I have given him the maximum of two doses now and it has been 1 week. I think that the edge of his fin looks less ragged and the black spot is going away, but who knows. There is no clear new growth yet. I also think that Flame is pretty old, as he has always had very large fins, and is not really fiesty. He loves it when I talk to him and will swim and spread his fins the whole time. He eats great, and begs for food. He does not however blow bubble nests anymore. He flares at his reflection but will not play with or attack anything (laser, my finger, etc.).
I have had pH problems, and after ageing my water the pH is at 7.6. Flame seemed to blow bubble nests only when it was lower. I have given him time to acclimate, but have only found the startings of a nest, and seen him blow the occasional bubble at me when I talk to him. It has been close to two weeks. He always acts happy when I see him though

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I feed Flame bettamin flakes as a staple, and bloodworms in place of his morning feeding every other day. He is in a heated and filtered 5.5 gallon tank with silk plants. I am cycling a 15 gallon planted tank for him and want to get him a few tank mates. This tank will have driftwood, so the pH will likely be slightly lower. If he does have fin rot, is it contagous? Should I forgo the tank mates? Oh..ammonia in his current tank is 0 as is nitrites. Nitrates are 5 and pH is 7.6

. I do 25% water changes once a week or as directed by the medication that is in the tank now.
I think that I am doing everything right, but I will leave this to the more experienced hobbyists to decide. Should I just stop the medication and let nature take its course, and just give Flame the most comfortable environment possible? I am really attached to this little guy and just want to do what is right. Also, have you ever heard of a betta being affected by a pH of 7.6? Are bettas just really hard to keep?? I'm sorry that this post is so long, but I felt that I should just cover everything that I know will be asked later in this one post. Thank you.
PS: A long time ago my parents got bettas for us and they lived several years in unfiltered, unheated, 0.5 gallon vases, shudder :( . Go figure, when I do everything right, everything goes wrong. Bad luck or what?