tangs need at least 75 gallons
mandarins need atleast 75 lbs of live rock, with a well established pod population(i'd wait 1 year after teh rock), they most often will not take to feeding they only want to hunt their pods, very rarely can a mandarin be turned to feeding(healthily)
are you adding a sump or refugium that will help if your are getting a mandarin that will help amphipods and copods stay populated in your tank and help supply your tank with them for food. even if your looking for 1 that eats other foods ask the fish store if u can see them eat 1st most people loose them because they slowly die of starvation. i have about 110 lbs of live rock and still hesitant on getting one until the tank matures at least a year than i might consider 1. hope u find 1 that eats other foods. good luck
i agree...a mature yellow tang should have a 75 and up. A young one can go much smaller, however, you would need to either give the fish back or get a new larger tank in a few months. That's what I'm doing cause I'm a senior in college and will be moving in May. I have a yellow tang that is very small in my 46 bow. It is very spacious for him.
-Eric