Treating Bacterial Infection

I have a female betta who is showing the early signs of a bacterial infection. She isn't very well bred so it's not a big surprise that she has a weaker immune system

I was thinking about treating her with kanaplex. Do you think this is a good choice? I found a 3 in 1 pack for Metroplex kanaplex and garlic guard. Metroplex is a binder right? Do I put them on her food and feed her?
Garlic guard is to help with either parasites or increase appetite?
Should I QT and treat just the fish with symptoms? Or should treat both tanks? Total of 4 female bettas, 3 endlers, and 6 platies

 

Why do you think it’s bacterial?

 

Not sure what else it could be.
Shes lost a little weight, which I know is usually from parasites, and the scales along the very top of her body are lifted a tiny bit.
I've had this happen to another fish and as time went on the drowsy hot worse. I want able to buy any meds at the time though. Ended up euthanizing him.

I don't know what else it could be or how else to treat her. Today her scales are just a little bit more lifted so I might do an epsom salt dip

 

The scales being lifted points to dropsy. Have you looked into that?

 

Dropsy is a symptom not a disease. I'm trying to treat whatever is causing the "dropsy"
Sorry for the late reply I've been gone all week for family/a wedding.
Since returning she has lost a bit more weight and seems a little more lethargic.
I'm finishing a epsom salt bath for her now

 

Metro is not a binder, its a antibiotic that is used off label for fish to kill internal parasites
It all sounds like a waste of money to save one betta, it could just be getting old, they only live for 2 years max......