[VAL] Water tank opening

[Allen McCann <kb0pmj@xxxxxxxxxx>]

1976 23' Land Yacht
Since I am new to airstream - but not new to RVs - I
have a couple of questions. The first question is
about my water tank. There is a opening under my sink
that looks like it is connected to my on-board water
tank. The problem is the opening is a plastic open
fitting that could let dirt, shavings, or whatever go
directly into my tank. Is this something I need to
close or is it an air source or what?
Also it is my understanding the floor of airstream's
is made from 5/8's plywood. But when I bounce on it it
seems to give a little. I don't see any evidence of
water damage but I wonder about whats happening on the
bottom of the wood. Should the floor be "rock solid"?

Thanks,
Allen