I wouldnt medicate, just do frequent water changes and add aquarium salt ... i also think your water params will be too jumpy for a 7 inch Army in a 10 gallon tank ... if you have a larger tank i would suggest moving him ASAP ... not that i think it couldnt work, i just think it probably wont and a 10 gallon isnt nearly large enough for him, and as stated his feeding and waste will most likely cause the water parameters to jump around, therefor stressing an already fragile fish, especially if he does have fin rot ... better pics would help ... it is def a good sign that he's eating, now you need to make sure his pooping out what he just ate doesnt kill him
Sent from my SCH-I605 using MonsterAquariaNetwork App