"Flow" questions for my tank

I hear all the time that you can never have "too much" flow in your tank. I currently have a 14G Biocube and since I'm going BB, is two hydor koralia nano 425s and a sicce syncra 185 gph return pump enough for my tank? Not enough? Too much? I don't want to go overkill because too much of something can be a bad thing, but I just would like some clarification on this. Thanks guys!