in my opinion I'd say at LEAST a cage the size of the one I have for my 4. It's 34X19X36. But the width for a tiel needs to be larger and the barspacing I think I read 3/4"? Look the spacing up though. I don't know as I don't have a tiel. =]
Lemon, Lime, Paradise, Blizzard, Oreo, & Vanilla
I LOVE Skittles!