closed loop method

[BBQHILLBILLY]

scenario:
2 1in holes drilled on bottom glass for closed loop.
will not drill more holes.
external pump 1900gph

Flow Chart

1/2 " PVC
3.5 GPM
210 GPH

3/4" PVC
6 GPM
360 GPH

1" PVC
10 GPM
600 GPH

1 1/4" PVC
20 GPM
1,200 GPH

1 1/2" PVC
30 GPM
1,800 GPH

2" PVC
60 GPM
3,600 GPH

2 1/2" PVC
100 GPM
6,000 GPH

3" PVC
175 GPM
10,500 GPH

What is the best method to plumb this closed loop?