Flame Angel disease???

[ReeferDre]

I have been in the hobby for 3 years and never have come across a problem like this. I have a 20 g nano I use a protien skimmer and a power filter and have for 3 yrs I have a 150w MH and 4 24w t5 actinics plenty of live rock cleaners including a cleaner wrasse lps sps and softies.
The tank is 8 months old and I purchased a flme angel It looked great at the store it was home for 3 days and started to look like there was ich on it but i've never had anyother fish in the tank that were sick there is a lion in there too by the way(i know no quarintine tank)have no place to put it) The spots were grouped together then the next morning it had a hole through the fin where the goup of spots was. The cleaner wrasse did not pick at the spots at all even though the angel courted it. The next day it was dead. I tried organic ich control and a freshwater dip. Any ideas It happened to a friend of mine as well.