My yellow tang has developed some brown patches on his side by his dorsal fin and his tail fin and he keeps rubbing against the rocks and the sand....what should i do? Does he have a parasite...i have CFX Parasite Terminator that was used for the tank before i got it...should i use it??? Will it kill my Camel Shrimp?? Thansk...i dont wanna lose any fish....ive lost 2 reef chromis for some reason 2 days after i bought them....any suggestions/answers?