Rodger;
What rainbowchaser(Jim) said. You may also want to place the weight forward, centered or rearward to change the action. I just tied a beadhead soft hackle with 8 turns of .015 wire behind the bead as I want it to sink head down(don't ask why, cause I don't know!!). Now I'm going to fill the sink with water, tie on some 5X flourocarbon tippet and see if it worked!