I usually go with #10 monofilament no matter what the color or conditions are. You might ask "why" especially if I'm in clear water, but this bait has treble hooks, and you're going to be putting it to the bottom, so you're gonna get hung up. When I go with #6 or #8, I loose a lot of lures. #10 prevents that. There are times when I don't use that line, though. I usually cast these on a spinning rod but you can use your baitcasting gear because they're really narrow and front heavy, so you can cast well on a baitcaster anyways. If you're doing that #10 to #12 fluoro works well. Most conditions (more about this later) where you'll wanna use a blade bait are lightly stained or clear waters anyways, so this works out fine. A good 6 1/2-foot medium-heavy power rod with a moderate tip works well to cast the lure a long ways and detect the changes in vibration.