Faster water flow might help you out some too. What exactly do your home made lines consist of? Any pics of the install?
For my short homemade section I used 2 runs of 4"x 10' PVC pipe, 1" pex lines in each pipe, each pex line had the same type of closed cell foam shown in my earlier link but was thicker, then the foam and pex was wrapped with red Tyvek tape just to keep them together. Then they were slide into the 4" pvc and buried 8' deep in gravel. Used long sweeps at OWB so I could remove and replace if needed. I also ran electrical and a pull rope in the runs in case I wanted to add something in the future. Also ran wire to the pump inside for the generator but been too lazy to hook it up.
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