Hello I am new at this...but here goes I just installed a grundfos mq-45 booster pump. It is 1hp. It has a precharge tank built in of 25lbs. I have a 86 gal bladder type tank precharged at 38lbs from factory.I am drawing fro a adjacent cistern. My question is since the pump is factory set to start pumping at28-30 lbs. should I lower the bladder pressure tank to 2lbs below the cut in at 28lbs as instructed by the tank manufacturer? EG lower the precharge to 26 on the pressure tank? thanks for any help.