and this is why i asked here...

http://www.orvis.com/intro.aspx?subject=2107

this just confused the sh!t out of me... so if i get a line for trout in large lakes and rivers, its a 6# line, but my rod is a 7# (all 3 of them), so can i even put the 6# on a 7? will it work correctly? will a 7# line not cast smaller flys for trout?