I had that pineapple ornament!! And that also looks like columnaris to me... that isn't the best news to be honest...
feed medicated food like Medigold or Romet-B, treat with Pottasium Permanganate (see description in the medicine section), injection of antibacterial medication if available. Melafix will also work well in aiding the infection.
Very clean water and maracyn 1-2, used together, was a very effective treatment for columnaris. within 3-4 days the telltale "threads" blowing in and out of my comets mouth had disappeared. meanwhile, his fins perked up and he started eating regularly again. salt dips at a solution of 1.5% for 5-10 minutes (or until the fish stops swimming, even after a nudge or two) really helps to clear up the heavy slime coat that is most likely prevalent. the dips can safely be used for up to three days at a time (before, during or after treatment). if the slimecoat still persists, let it rest for a few days and continue with another round of dips.