Question on what you set your discrimination to in 3, 4 and 5 tone mode. I find (obviously) the higher I set it, the more depth I lose. I've been setting mine somewhere between 5 and 10, but I read where folks have been setting theirs as high as 21. I tried that and it seemed like I wasn't finding anything deeper than 5 or so inches. Everything deeper than 5 inches was coming in with a very weak, jump signal. I'm still learning the machine as I just bought it several weeks ago. What is your normal setting for discrimination in 3-4 and 5 tone?