Ive amazingly and by chance of a miracle saved my 2 male guppies from columnaris...first time with guppies, first time with a disease like such. I started with 8, overstocked the tank before I knew about the cycle, 6 died within the first week each 24 hours after contraction. It was an ugly and brutal disease, yuck. Well anywho I know you should never use primafix and melafix with bettas, but I used those products along with a massive amount of AQ salt and 2 males survived! They are still alive and kicking 4 months later :) ....
Not saying use those products! I know the fix's arent the best choice for bettas, Just saying saving a fish from columnaris may be rare but can be done! But I really hope I never see that fuzz stuff again ugh.
I have used 1 tablespoon of Aquarium salt with betta's when healing some massive fin damage along with IAL ...it actually happened by accident, I was told to dose 1 teaspoon and thought it was 1 tablespoon and dosed it...fishes all lived, only 1 seemed mildly stressed and they all healed up really well! Since then ive felt safe dosing 1 tablespoon (3 teaspoons) when I feel its necessary.
I imagine 4 is okay? But then again ive never tried 4, but seeing my 3 fishes do okay for a 10 day treatment of 1 tbs daily after 90% water changes id assume its doable.
He looks really good! Glad he healed up :D