Sick Betta! help please

[Shortie55505]

My betta Blue has a white patch around his mouth (in the light). His back fin is looking a little shredded. he's been a little less active. we feed him 4 pellets a day of betta food. we've been using quick cure cause we had white worms in our tank. and we've added aquarium salt. we have a 10gal tank with one live plant, filter, heater, two caves, white gravel, and one betta named Blue.

[Dtld9]

What are the water parameters? How often and how much do you do in terms of water changes.