265 gallon setup

[Ruth]

Colin, I am by no means an expert on Tangs but I am sure that Naesco (sp) will chime in.
I have a Yellow and a Hippo in my 230g and they get along just fine but they are from different families and have a different colour and body shape. I think if you stay away from tangs from the same family you are usually OK.
That said I do know that purple tangs can be very aggressive so you may want to add that one last. Achilles are my all time favorite tang but I don't have a system that I could add it to as my Yellow tang is a real SOB and attacks anything even remotely similar in colour and body shape. I found out the hard way when I tried to introduce a Moorish Idol to this tank. I ended up moving it to my 190g and he is still doing great. Achilles are also the most prone to getting ich so quarentine is a must.
There is a thread on RC about Moorish Idols but I haven't read it for a while - lots of good information though the last time I did look at it.
Emily B (Deb) just lost her Moorish Idol yesterday and it had been kept in captivity for about 4 years which is a really long time for this particular fish - they have a very poor track record. Mine is about a year in my tank, although I did loose one to the SOB yellow tang before I got this one. Also as a note I did not order either of these fish - they came in with a shipment to one of the LFS in Vancouver and they asked me if I would try them given I have fairly healthy large systems.
Don't know if that helps any.
What kind of a skimmer are you looking at?