I have a small yellow shoulder tang in a 10g QT .I purchased the fish 11/18 and all was good. I ramped up Copper to 2. 22 over 2 days. The fish looked good and was eating. It hid all the time but it was eating the nori I was feeding daily attached to a frag plug. 2 days ago I noticed the nori hadn't been eaten. Today I decided to get him out of hiding and take a look at him and saw he has Popeye in both eyes. I'm using an ammonia badge which is showing good (I don't have an ammonia test kit as I've never tested after cycling a tank) and have an established sponge filter in the tank. The tank was set up just before purchase using change water from my other tank that is clean. It was run fallow and all fish treated with copper early this year after velvet. I've never dealt with Popeye and Google is giving me so many different opinions on treatment I wanted to check in here for advice on how to treat. Thanks