For a long time I've believed that cryptocaryon can survive dormant in a fish's gill mucus for a long itme, even this is not part of the often described life cycle. I'd bet the new tank reactivated it in the blue hippo, a fish which seems to carry this parasite 99.999% of the time even after appropriate quarantine and treatment.
My limited experience has generally been that capture/treatment is worse than the disease. As long as they are eating, keep adding garlic and ginger to the food and try to ignore the white specks and the scratching. Obviously any fish getting into big trouble -- i.e. not eating, labored breathing -- should be removed if possible. I have also used Kordon Ich-Attack with some success. It is reef safe although since it requires carbon and skimmer to be off, and being an organic additive you will see nosedives in redox and RTN may manifest from that.
I don't think UV has much use in a reef system. While it normally would not hurt to add it, in a Zeo system it will destroy the free bacteria in the water column. Ozone is even worse as it will affect not only bacteria in the water column but potentially elsewhere. My soft corals and filter feedings seemed very happy when I disconnected the UV, bacterioplankton is an underestimated source of food!
I think the best way of eliminating ich from a system, if this is possible, is to let it run its course. Ignore the few spots that show up now and then. After a year of no new fish additions, the ich organisms should all perish from apoptosis as they have a limited number of reproductions before death without fresh new DNA.
Good luck.
My limited experience has generally been that capture/treatment is worse than the disease. As long as they are eating, keep adding garlic and ginger to the food and try to ignore the white specks and the scratching. Obviously any fish getting into big trouble -- i.e. not eating, labored breathing -- should be removed if possible. I have also used Kordon Ich-Attack with some success. It is reef safe although since it requires carbon and skimmer to be off, and being an organic additive you will see nosedives in redox and RTN may manifest from that.
I don't think UV has much use in a reef system. While it normally would not hurt to add it, in a Zeo system it will destroy the free bacteria in the water column. Ozone is even worse as it will affect not only bacteria in the water column but potentially elsewhere. My soft corals and filter feedings seemed very happy when I disconnected the UV, bacterioplankton is an underestimated source of food!
I think the best way of eliminating ich from a system, if this is possible, is to let it run its course. Ignore the few spots that show up now and then. After a year of no new fish additions, the ich organisms should all perish from apoptosis as they have a limited number of reproductions before death without fresh new DNA.
Good luck.
The worst of the lot is my PBT and my Hippo Tang. 
