Congratulations on the win!!!

I would make about a half-pot sized bet in that case. You don't want to scare him off in case he only has the Ace and is still drawing to the flush... (and hope he hits it on the River). Or if he has something other than the 'nut' flush i.e. even if he has K,Q and you shove there, he's going to assume you have A,x and perhaps fold it.

Nicely done in my opinion.