Vectra L1 plumbing question

[chucklez]

I have a Vectra L1 that I think is great, but want to optimize my plumbing. I think I am getting to much back pressure hurting my flow. L1 has a 1" return. Each tank has 2 3/4" returns. I have a single return line running from the L1 that currently has 3 1" tees and a 1" 90 at the very end. Each 1" tee has a 3/4 bushing. Each return also has a ball valve to control flow. Make sense so far?

I want to add sweeps rather than tees but they dont make 1" sweeps. Atleast readily available and priced reasonably around here. A select few specialty places online, but shipping and price is exorbitant. So I am thinking of taking that 1" line, using a 1.5" sweep and then adding a 1" bushing to each end or a 3/4" on the sweep end. How would this affect my flow? Negatively? positively?

 

[mfinn]

If you used the optional fitting pvc from ETM and changed the return to 1-1/2 all the way until you need to reduce it down to four 3/4" outlets you would get better flow.