do you have another upgrade planned next year? if not i would say no. casn you technically get away with it, sure...but a naso and any tang for that matter will quickly outgrow a 65 gallon tank. many will say you can and say well i have done it for years, but that does not mean it is right or the best practice. i had 2 tangs in a 90 and i thought that was a bit much IMO as they grew and in my 210 i plan on having 3-5 depending on what types. to best handle one you would need to make sure you give plenty off swimming space so dont over do the rock and make sure they are well fed with a good skimmer and filtration system. this will make sure that even if they are cramped a little they are healthy enough to fight off anything the stress may cause. remember, big fish like tangs poop alot so if your system cant keep up with it not only with the tang suffer but all your other inhabitants as well.
