MACCAMY99

As part of a service last week, I changed the fuel filter on my 99 scooby. Pulling of the hose connected downstream of it, there was quite a lot of fuel in the pipe which I drained into a glass beaker. The fuel appeared to be very cloudy which later cleared leaving a black/brown silt in the bottom of the beaker !
Since this was downstream of the filter, I'd be surprised if it can from the fuel tank so maybe its from the hose itself ?
Has anyone else experienced this ?