I have this fish in qt. Using copper power steady at 1.75 for 3 weeks. Did a water change yesterday. The water was pretty stirred up and it’s only a 30 Gallon tank. Premixed copper in new water prior to filling the tank. Today I notice an outbreak. I also have a smaller blue tang and yellow tang in the tank. Neither of them are showing any signs. Is this hlle? The white spots have me concerned.