Hello, I know this is a common problem with powder blues and regals. I'm doing 10 percent water changes each week. Feeding a wide range of foods which my powder eats. Even soaking shrimp in garlic. Any tips? I do have cleaner shrimp and a cleaner wrasse. The wrasse isn't aggressive anymore but if a fish lets it, it will clean away. The regal blue doesn't have any visual signs of ich. Just the powder blue and Kole tang ! All other fish appear to be good to go !