White cotton like growth in betta fish

[John1101]

I started to notice a white cotton like growth in the side of the betta fish. I could not find a solution for this problem. Isolated the fish treated with api ich for 7 days  but it’s not working out. Treated with cupramine for 7 days bot no good. and api betta fix for 7 days but no good. The white cotton like growth is still same . What is this growth and how can i fix it. 

[Colu]

Looks like the start of a tumor they are really common due to inbreeding what I would do is add some Indian almond leaves as they have antibacterial and antifungal properties depending on the quality of the leaves you might have to add one leaf per gallon to get a beneficial effect and I would add some aquarium salt 1 table spoon for 3 gallons for a week and just monitor @John1101