What line am I using?
How often do I change lines?
It is a balancing act. You can't put 20 lb. test mono on a small spinning reel. I'm using the 20 lb. test on a large 4500 Shimano Baitrunner. My Shimano 3500's work well with the 15 lb. test line. Your spool should be marked with ideal line choices as well as the yardage it will take.