Sick Betta Fish, fin rot?

I am pretty sure my betta has fin rot, and although I've tried treating it, it hasn't gotten better.
She is in a 2 gallon tank (and i know that's too small, but it's just a quarantine tank and I'm planning on moving her to a 15 gallon as soon as she's healthy). As for the parameters, the pH is at about 7.5-8.5 (I'm using strip tests, which I know are far from accurate, and those indicated a pH of 8.5, however the water in my city is supposed to have a ph of 7.3 and I've been using catappa leaves to try lowering the pH), the GH is at about 20, the Nitrite level is at 0 and the Nitrate at a little under 20. Also, the tempretaure is at 25°C/77°F. The tank has been running for 2 months, because she previously had columnaris and I had to separate her from my other fish. After I treated her for that her fins seemed to be getting better, but a couple of weeks ago i noticed that she had fin rot.
I tried an aquarium salt treatment for 7 days and then I waited a week but her condition isn't getting better. Should I try another treatment, and if so, what should I use?

 

You could trying increasing the salt concentration?

 

You could trying increasing the salt concentration?

Won't she get salt poisoning if i do?

 

Mild fin rot will get better just by changing the water often (for a 2 gallon hospital tank - that would mean small daily changes) and adding Indian almond leaves/catappa (which you are already doing) or roobios tea.

If it is a more severe case, then you just might need to use an antibiotic that treats gram negative bacteria (maracyn 2, kanaplex, or maybe API Fin and Body Cure - whatever you have access to). Sometimes it takes a while to eradicate if it is an advanced case. Since your fish was already infected by colmunaris, she probably has a weakened immune system.

Pictures would help if you could post some.

My go to is usually Kanaplex. Even though it is marketed as the strongest of medicines, it really isn't that strong, and often requires more than one round of treatment, if it is a really advanced case.

I hope this helps!

 

Thanks for the advice!!
I've attached a few pictures of her. The first two are from a few weeks after the columnaris treatment, and the other two are from a few days ago. (her dorsal fin is so small because it got damaged by columnaris).

 

Poor little baby!

It's not unusual for a betta, who has had an injury/issue, to clear one thing, and then get another due to a weakened immune system.

Make sure that she is eating really good, healthy food to help build up her immune system again.

If you continue to use salt, you must be careful not to overdo it.

Start treating her with the daily water changes, and the Indian almond leaves. I would do this for a few days to see if you get any results. If you do not (you do not see any re-growth), then I would go to a medication.

If you see anything on her body at all, any sign of body rot, go immediately to a medication.

I hope she gets better!