Tangs are the best 100% reef safe algae cleaner.
No offense to you, but this is 100% false in regards to them being "reef-safe"...
Any comparison to their natural environment is just ridiculous.
Really?
So because a fish will swim in 15 + foot runs at a time before turning to head the other direction while swimming at a rate of 15 mph as they're defending their territory in nature we shouldn't take that into account in captivity?
Comparing a humans life-style to the high energy life style of a fish that's
evolved to swim far and fast is ignorant.
I totally agree with your "appropriate size" upon purchase statement, but you have to take into account if your tank is appropriate size as well, which many times, it is not. Along with the rabbitfish statement; that's rediculous that someone would mention to
'not put a tang in your tank, put a rabbitfish in,' when a commonly sold
Siganus puellus can attain 10+ inches easily in captivity. Most tangs are a very high energy, fast swimming fish that do not belong in our tanks.
It's a fact that tangs swim as they do, just like it's a fact that Great Whites eat seals... to me this is not a hard judgment call.
If you want a tang, I would look into purchasing a small one (around 2") in the Zebrasoma (Purple, Yellow, etc..) or Ctenochaetus (Tomini, Kole, Chevron, etc...) genus.
This is good advice assuming you know that they'll outgrow a 30" tank, in which I agree with Ian's statement about puppies, but yes, that is MO.