I've been treating my betta for fin rot and now notice a white/gray spot on one side of his head. Could this be related to the fin rot or something else? I've been treating with gradually adding salt on the 7 day plan and he otherwise seems to be doing notably better with improved appetite and activity. The plan is to move him from his 1 gallon bowl to a 3.5 gal heated and filtered tank at the end of the 7 days.