no the pressure is fine....in fact that's actually good. i have well water and the pressure is barely 40 +psi so i installed a booster pump and it usually pushes above 80 psi now.
are you using a container (plastic) to hold the ro/di water? i remember reading somewhere about certain plastic containers leaching phos.
I tested the water straight out of the ro/di to eliminate the source being my container. My phos are extremely high out of my tap at 1.8+. my ro/di is reducing this significantly, just not enough.