MY FRENCH HAS A WHITE SPOT ON ITS FINS.IT IS COTTON-LIKE AND THE AREA IS AROUND 2-3mm IN DIAMETER.NOW IT STOPPED FOR EATING ALREADY 5 DAYS.I AM SURE IT IS NOT ICK.CAN ANYONE TELL ME WHAT IS THE DISEASE AND HOW TO TREAT IT? IT IS MY FAVOR,PLEASE HELP!!!(MY TANK IS HAVING FISH ONLY,280Litre) :(...