it wont be enought to fire up the beckett. the water that flow thought the beckett will experience super high pressure thus will result in a huge headloss. as for md55 not being able to match your overflow, you are wrong again, alright the flowrate might not be that high, but its a pressurated pump thus meaning that it can withstand high pressure and suffer relatively little headloss. sooner or later i bet you will be running a pump with the beckett as the result from the overflow pipe will be not as good as you think it will be. just my $0.02