Fibers in wellwater?

Have not had any issues in 4 years but two weeks ago noticed water from tap being discolored, had softener guy out and fiber material almost like cotton plugged up the Venturi screen. Cleaned it out and water cleared up. Now a week after water cleared up we seem to have the same issue. Does not seem to be magnetic and the fibers will burn. Anyone else see this before? Could it be from my pressure tank? From the well itself? Thank you!