Tang are strong and fast swimmer and thus needs the space to swim if not they tends to loose color, stunted growth and die. Even the smallest tang (Ctenochaetus tominiensis) when fully grown can reach 13cm.
Thus for 2ft tank it is not adviseable. In fact, in Reef Central the reccomended minimum size is 4ft.
wat other fishes do u recommend for a 2 feet tank?
pH7.5 enough?
thought salt water fish need 8.2? or something close?