what rating suction line should I use?

I am scrapping my old poly line going from my well to the pump. I am tired looking for the leak. I have about a 75 feet length to go. Should I use 100 psi or 160. Whats the disadvantage if I go with 100 psi. Its a shallow well with a 3/4 horse goulds jet pump. Appreciate any suggestions.....

How deep are you placing the pump?

Rancher

its a shallow well pump

not submersable, its in the gaarage.....

I wouldn't go less than 125 psi and if I was buryng it more than a say 2 foot deep or where it would ever be run over with more than a garden tractor, I'd go 160 psi. The difference in cost isn't worth a few days looking for a leak with a shovel, right?