At most crappie tournaments we weigh in 7 fish. Some folks try to keep too many fish in the boat and overcrowd their fish and make them weak. I try to not have over about 10 fish in the boat most times. I use a balance beam to cull fish most of the time, it seems to be most accurate to me. I have tried to use digital scales but its too difficult for me to remember the weights of the fish. Heck some days we don't have 7 fish so we don't have to worry about it. Where are you going to compete in crappie tournaments at?