I'll trade a 6060 for your 6080. The 6080 puts out 2,500GPH, not 1,250. My 6060 puts out 1,600gph. So you'll see about a "50%" decrease in flow. I say that because your estimate was half what Tunze states so you will see a reduction in flow in your tank equal to about half what it currently is. The 6080 would be a great pump for my 400g when it gets here. Win/win for both of us.