So I was bored and dropped a gopro into pond today, and I saw a round, white puffy spot on one of my koi. I have no idea what it is, and if it is old or what as you can not see it without video of side. Any thoughts, advice, welcome.
Water is very good, zero ammonia, frequent water changes, covered for winter with filtration going and filters cleaned often. Water temp is 54* currently. Fish seems super healthy, hoping it is an old scar maybe?