Hey Linda,
If the little plastic filter turns black, its probably bugs unless you are using biodiesel.
When it goes black, best add the biocide, run the car to get it through the system, sat 100 miles of normal use & then change both filters. If this happens regularly, change your fuel supplier, that is how the bugs get there in the first place.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving