HELP... Ich ??

Can someone confirm this is the dreaded "ich"? This started about a week ago and has almost totally healed by yesterday evening. This morning it made a 180 and attached is what "Coco" looks like right now... Current water condition is:
nitrate- 20
nitrite-0
ph-8.4
ammonia-0
water temp -77
salinity-1.022
I made a 20% water change this am right after just to be sure... Coco has been eating just fine and is very active.. The rest of the fish have no sign of having any issues. Thanks

 

here's a link to another thread that will help. Looks like black ich to me being on a tang and all but I'd ask these guys.http://www.google.com/imgres?imgurl...a=X&ei=2hgzTPSHHMXflgfSjKm_Cw&ved=0CDMQ9QEwBg

 

yea kinda looks like tangs disease but hippo are known ich machines so just make sure hes eating well and he should kick it.

 

Hope coco can fight it off. That's a nice lookin fish