Only two fish that made it thru the velvet were the yellow coris and the leopard wrasse...wondering if it's something to do with them both sleeping in the sand??
The sand can play a role in that it "sloughs" off some of the slime coat when they hit it (sand), but moreso has to do with the scale structure on (most) genus of wrasses.
Nice new fish list, glad to see you got a couple angels in there