We have installed a whole house water filtration system for our well. The water goes from the well pump into a pressure tank (with a pressure gage installed before entering). It then goes into big blue 20" 20 micron sediment filter followed by big blue 10" 5 micron sediment filter, entering the pelican 600 carbon filter and then sterlight UV light. When the water is pumping through the filters there is noticeable pressure drop at the end it goes from good gushing to trickling and running down the hose. And there is also fast on and of switching of the well pump. All parts besides the well pump are new.
What could be causing suck a drastic water pressure drop?