This is now happening to my bass. Eating fine and growing fine but every bass I introduce to my tank gets this blood-red gill spotting and I want it to go away once and for all....My parameters are also fine.
Ammonia: 0-0.1
Nitrite: 0
Nitrate: 0.34
Ph: 7.1
Temperature: 85 Degrees
Diet: Silver sides and occasional feeder goldfish
I dont know if this helps at all but it appears to make the bass itchy....but its definitly not Ick.
Seems to affect larger bass more quickly and progresses farther on them.