IMHO, and, FWIW, "The Hinckley Co.", recommends nothing smaller than 10 uM on the secondary filter system for their boats in winter storage. To get an idea of how small a 2 uM filter is...
please see below...and this is excerpted...
Anton van Leeuwenhoek provided a microscopic description in 1674, providing precise description of red blood cells, approximating their size, "25,000 times smaller than a fine grain of sand". A typical human erythrocyte has a disk diameter of approximately 6.2-8.2 µm[27] and a thickness at the thickest point of 2-2.5 µm and a minimum thickness in the centre of 0.8-1 µm, being much smaller than most other human cells.
So, if I" bleed" into my fuel system by perhaps cutting my finger tip during servicing filters, I'm not going to "sweat" a red blood cell in my fuel line. In fact, it would likely provide a good source of fuel. So. I go with a ten uM on the secondary. And I completely agree with the concept that before going offshore, clean your tanks...
This unfortunate incident was a series of poor decisions on the part of the delivery captain, and the crew should have mutinied before it was too late. How many times have you folks, on this BB board, been crewing in races for someone who did not know what they were doing? I certainly have...
Got tired of that quickly, and sailed to...somewhere in Maine
mnh