In well over 800,000 miles of MB diesel maintenance, my experience has been that changing both fuel filters every 25,000 miles will prevent the situation you encountered.

The only exception to this would be bad luck that causes you to get a REALLY BAD tank of fuel somewhere. I have never had that bad luck,

As far as algae goes, I have seen it before. You will say BB sized grey particles in the pre filter. When you see these, simply pour a can of bio gard in the tank to kill the algae.

This is all you need to know to keep your tank and filter system in shape.

Good luck,