Looking for some information on my new Sprinkler System, I just installed a new 2hp shallow well pump, I only have Zone 1 completed it consist of
 Nelson 6000 Series Heads (Gear Drive) 3/4" inlet coming off of a 2" main to a 1-1/4" elbow reduced to 3/4 to the head"; inthe open part of the yard
 Nelson small popups coming from a 2" main to 1-1/4" line with  inline 1-1/4"x1-1/4" x 3/4"[fipt] T's reduced to 1/2" head; near the house for the flower beds
I turned on the pump got the pressure to 45-50 psi then opened the valve and it dropped down to 10-15 psi. The small popups seem to be ok but the gear drive units seem to be very low pressure and do not shoot very far, I beleive this has to do with the low pressure. I bought the extra HP pump hoping this would fix any issues with low pressure. What did I do wrong or did I forget something...I'm pretty new to sprinkler systems so please help.