I have had my system for 3 1/2 years. Until the last 6 months it worked great. The problem is the water coming out is just a trickle. I've changed both filters twice with new ones and still the flow is just a trickle. What is wrong with the system? IS it something I can fix or must I replace the whole system? Any advice you can provide will be appreciated. Thanks...

Frank Klepach link removed