water filtration system particle filter turns reddish brown in 3 weeks
 

I have water filtration system of a white particle filter and a charcoal filter cartridge. Within 3 weeks the white filter turns reddish brown. Water co. comes out and flushes the road pipes and it helps a little. I've been complaining for 4 years, water was tested into house and it meets standard.
We are on a cul de sac and my neighbor across the street has the same system and his white particle filter stays white for months.
Has anyone else had this problem? I was given a phone number to call for references to outside companies which would make it my problem