My common pleco is shedding his stress coat ive read that when they do that theyre getting rid of diseases and i had a huge fungal infection in my tank that killed 2 of my tiger barbs and almost killed my fire mouth and jack dempsey

my pleco is about 6 years old ive had him since i was about 6 or 7 and im 13 now. Dont underestimate me because of my age ive had alot of cichlids and all grew to be 12 inches then i sold them

pleco= 8 inches
jd-= 4 inches
firemouth= 3 inches
parameters are fine amoniass at 0
ph is at 7.0
and nitrate is at 0