Your pump is good enough. You dont want to have a high turn over. For your water filtration. You let the display tank circulation pumps take care of that. I run a Sicce 1.5 on my nano 24x16x14 with external overflow on a 1" drain. Works just fine.
it truly depends on placement of coral and rockscape in the tank but I like to ensure that I don't get any dead spots. I'd rather have multiple powerheads instead of one large one, but that's just me
