ME TOO
I too am dealing with this problem. I have researched having someone polish my fuel using a polisher system. The expense for this is causing me to look for other options. I think I have decided to drain the fuel tank out of the drain plug in the bottom, draining the diesel into fuel cans. I am then going to add a substance that I saw at Defender called ALGAE-X® AFC-705 Fuel Catalyst that supposedly kills all algae, bacteria, and fungus. It also claims to break down any crud in the tank so that it can pass through the engine without harm. I am going to buy 3 or 4 extra filters for my Primary Racor filter system and change often during the season. The diesel in my tank currently has been in the tank for over 4 years and although I have had no problems I am experiencing lower power and some smoking. The problem with polishing your fuel aside from the cost is that the baffles in the tank keep any cleaning action provided by reversing the flow from cleaning the whole tank.