Thank you for this!Thanks, these help.
In the last powder blue image, I can clearly see ich. The copperband shows ich on its tail as well.
What treatment options do you have?

I'm gutted but glad to get confirmation! Is there any short term relief I can provide whilst I look for a quarantine tank for all fish to leave the tank fallow for 80 days... My understanding is that this IS the ONLY cure?!
IF I were to treat the display tank with copper for this? It may be easier to remove my prize corals and inverts and risk killing the plating montis that cannot be moved, is that a possible scenario?


