My personal record is 20 minutes-true story! One of my best tops produced 77 fish in less than 24 hours. Other tops have resulted in the big zippo-its all in the location. Five top ratio is: 1 goodun, 2 pretty gooduns, 1 so-so goodun,1 no goodun. Best top material has proven to be oak limbs or other hardwood. The limbs are wired together with scrap copper wire and anchored with a cinder block. Placement is always on ledge adjacent to deeper water. Also, the bigger the top the better.Hope this info helps!