"Jerry Baker" wrote in message news:0HURg.3296$Vk4.2531@trnddc01...
Pszemol wrote:
Have you used thin-walled PVC or regular SCH40?
SCH40 1" pipe has very thick wall - its internal diameter,
where water flows, is similar to thin-walled 3/4 pipe.
Replacing regular schedule 40 pipe with thin-walled
one and THE SAME OUTSIDE diameter will make a big
difference in the amount of water the pipe can handle.

The pipe is 1.5" connected to the 1" bulkhead with a reducer bushing.

This reducer will be a bottleneck of your system...
Unless it is from the thin-walled irrigation pipe system.
Check its internal diameter. Think of it as half-open valve.

Anyway - your pump at the hight of the tank delivers little
over 300 gph (asuming there are not 90' elbows on the way).
This is way below what 1" bulkhead can handle, my friend.

Look at the weak points of your durso/stockman pipe design.