I have noticed there is a certain depth where you can pull through without sucking anything into the pipe. (that pisses me off)

Can people not create and manipulate a negative pressure on a pipe without sucking anything in it? I think if you pack too big, you won't get the flow of air. If you have to 'SUCK' on a pipe, its too tight. You should be able to lightly pull on it and get plenty of smoke. If I am alone, I pack small. But I catch hell with my friends if I pack those 'weak sauce' bowls.