It's worth noting that "recommended" sizes vary quite a bit internationally.
The recommended tank sizes for the larger tangs (in bold) from Danireef are 45G smaller on average.
Danireef is the most popular website in Italy about reefing, they collaborate quite a bit with reefs.com.
Their article on the recommended tank sizes for tangs is also available in English, in case you're curious.
I think it's worth noting because it does seem often than there's no other point of view on the matter other than what is being recommended in the US.
| DaniReef | Liveaquaria | Reef2Reef |
| Yellow tang | 80G / 300L | 100G | 80G |
| Purple tang | 90G / 350L | 125G | 80G |
| Gem Tang | 90G 350L | | |
| Convinct Tang | 125G / 450L | 125G | same as LA |
| Kole Tang | 100G / 400L | 70 G | 80G |
| Chevron Tang | 100G / 400L | 180G | 80G |
| Powder Brown Tang | 100G / 400L | 125G | same as LA |
| Achilles Tang | 125/ 450L | 180G | same as LA |
| Powder Blue Tang | 130G / 500L | 125G | same as LA |
| Blue Tang | 130G / 500L | 180G | same as LA |
| Orange shoulder tang | 130G / 500L | 180G | same as LA |
| Clown Tang | 130G / 500L | 250G | 180G |
| Sohal tang | 200G / 750L | 250 | 200G |