I have to agree with the others above, that clown tang is just asking for trouble. I keep tangs, but in a 180g tank, which I;d say is about, what 720liters or so? They are also the most aggressive tang you can get, it will give you trouble if you add any more fish.
I hate fish stores that say things are fine when they really arent, its so not fair to the buyer and the fish. :-(
Just my 2 cents, good luck!
180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18