I have a customer who installed a new 0.75 HP submersed pump in a shallow well. The well guy promised 12 GPM at 50 psi for the irrigation system. Now that the pump has been installed, we only have 7 gpm at 40 psi, but I am testing at the spigot that is closest to the water flow into the house. I'm sure the well guy will say that the spigot is reduced, therefore we will have less water. However, the same spigot produced 5-6 gpm at 40 psi before the pump was changed to the new one. Thus, I don't believe that the well guy is delivering as promised. Does anybody know how much more water I can expect from the well once I am going straight off a 1" line into the irrigation system? Also, I need to put on a filter and I know that will reduce flow - but by how much? I need 10 GPM at 40 PSI to be comfortable. Thanks for your help!