Jason,
I am looking at the Iwaki pumps. My aquarium is glass, but I already have four holes drilled for the return. So I am thinking of using one Iwaki pump attached to the sump and have it return to two of the return bulk head fittings, and then have a second Iwaki pump used for the closed loop. I will probably go with the intake design of your closed loop, and have the return split into two and return them back to my remaining two bulkhead fittings. Another question just came to mind, should I attached the chiller to the sump plumbing, or the closed loop. I know it does not really mater much, just which would be more benificial and easier.
I am looking at the Iwaki pumps. My aquarium is glass, but I already have four holes drilled for the return. So I am thinking of using one Iwaki pump attached to the sump and have it return to two of the return bulk head fittings, and then have a second Iwaki pump used for the closed loop. I will probably go with the intake design of your closed loop, and have the return split into two and return them back to my remaining two bulkhead fittings. Another question just came to mind, should I attached the chiller to the sump plumbing, or the closed loop. I know it does not really mater much, just which would be more benificial and easier.