Yes, it's a very complicated scientific principle referred to as "water is heavier than diesel fuel" principle. If water makes it to the main fuel filter, it should end up in the bottom part of the can.

As long as you don't drink a big gulp of water, it will never get to the IP.

I always love the way people think mercedes engineers are damn near retarded, and that after market junk is always better.

Just ain't so.

Joe