This debate will never end until thiers a penalty for mis-leading labels , and 1 standard Filter rating . Something like this Filter tested at Xpsi @ x volume @ x time = Mic on 1st pass %.
For example You can label your filter 2mic...OK @ what PSI and What %. as it stands now you can get 2mic rating at only stopping 1% of 2 mics @ 3psi, So the filter label/rates at 2 mic gets 1% of 2 mics and less then 50% of 10 mics on 1st pass. See how misleading this is.
When I decide to change our calibrating fluid for the Pump stand ,I have one of the most elaborate filtering systems (Simple but it takes all the high tech trash testing out) I contaminate the fluid with solids and water, Its capable of testing 3 filters at once 1,2,3 the 3 filter is The filter of My choice, 1&2 are candidates..1 of the most popular 2 mic filters mentioned on this site and other fails every time I tested them, I found solids in 2&3 pass this 2mic filter.
More filters the better the filtration, That's exactly what it is filtration, NOW stopping contamination is another. It would be rare to purchase contaminated fuel at retail locations that practice good hygiene, (scrubbing tanks yearly, correct pump filter, keeping the raiser and pots free of debris, ETC,) its the storing and transferring that most contaminates develop.
Here's picture of the fuel pot that fed My new 2013 with contaminated fuel, I demanded a simple, they refused until I called the Police, then Mnblue dip tank We did not find the water contaminates I was looking for But the torpedo had sold material that was clearly visible to the naked eye. If I would have NOT install the auxiliary transfer tank with AE-3AZL filter the fuel would have made its way to My factory Tank, The filter did exactly what was design to do it Plugged 100% shut, thus saving $$$$ the Truck was new and only had less than 500 miles.
Mnblue suck My tank dry and I went on My way. I had 66 gallons in the auxiliary tank (Holds 90) .The AE-3AZL filter plugged almost instantly when I started the Nozzle.
Every one want proof so here's some pictures