It started out like a spot of ick, then it became cottony. After I put in the salt, it sort of smoothed over just a little bit and the color became off white, a little creamy. It is definitely not a part of his fin - it is a growth on the outside, and it sticks out from the surface. It is probably sticks out about 1.0-1.25 mm from the fin.
Can you treat fungus with maracyn II? I thought it was an antibiotic, and the instructions/label say nothing about fungus - only fin rot, dropsy, pop eye, and a couple other (bacterial?) diseases.
Thanks for the complements on the koi! Both are fan tails, and the really sick one is orange, but is developing black patterning on his head.
I also received some bad news about the koi's parents, who live in Michigan. Apparently, the pond heater malfunctioned or shorted out, the pond froze over, and the parents died
Now the only survivors are my two guys and about 8 of their siblings in Michigan who were taken indoors for the winter.