Question on Zeobrite using Haywood filter

I have installed a Haywood filter (24 inch diameter) with Zeobrite as a fiter media last year. When ever the pool pump turns on I notice a brownish tint entering the pool return lines for about 1 - 2 minutes. I have backwashed the filter several times to ensure that the zeobite is clean but after a day of two the brownish tint is back again. I have also noticed that after several days there is a brownish material on the floor of the swimming pool. Is it possible that one of the lateral lnes is busted in the Haywood filter and if yes can it be fixed.