Here is my puzzle. I am running a GAST 1/4 hp (model 0523) pump to a 1/2 acre pond. My run is about 400'. I am temporarily using my 1 1/2" PVC water line for 300' then reduce to 1" PVC for the remaining 100' then distribute into the pond through 1/2" poly tubing running 3 diffusers (4', 6' & 8' deep). Works great but I can't keep using the 1 1/2" water line, so...

My question:
Does the order of pipe size from the compressor make any difference? Run 100' of 1" PVC reduce to 300' run of 3/4" PVC to 1/2" poly line distribution points OR reversed - 300' of 3/4" to 100' of 1" then to the 1/2" poly tubing?

I was told 3/4" PVC should be ok for my 400' run but I would like to use up the 100' of 1" PVC.