How did you go with your 'problem'?
I've got a similar problem on my 36 foot ketch
. It's only in rough seas when the tank is shaken that the filters block. My diesel
turns a rustic brown colour.
I'm slipping in a couple of weeks and then I'm going to empty my tank with a portable pump, then to 'Karcher' my tank, degrease, karcher some more. I'm then contemplating sealing the inside with a tank sealer. That's going to be difficult to do though because it's hard to get to the entire tank. Mine has two access hatches but they are only about 6 inches wide by a about three feet.
I don't think I have 'the bug', and since I reinstated the tank from its dormant state I've always added a bio additive. It was dormant for about six years as the previous owner connected a small 15 litre tank to it and completely sealed off the keel