I just checked the water 3 days ago right before a 25% water change. No ammonia or nitrites, minimal nitrates. After the water change I added a small amount of salt. Two days later the fish started showing these spots. The female cacatuoides also has some. The rainbows and corys are all fine. I was wondering if it was some type of worm or fluke due to the brown spots with white centers. Damn, I really don't want to have to nuke the tank with antibiotics.