Hardest fish to keep & what is your oldest fish

[fdiddy]

Hardest fish for me to keep so far would have to be a Kole tang. Don't know why, other tangs seem to do great, but I've tried two of these fish and they don't seem to do as well. Longest fish I have, and they've been in there since I started the tank, is a yellow-tailed damsel and a gold stripe maroon clown. Both approx. 1.5 years old. Been through a tank crash and an upgrade to a 160g from a 40g.