Size of weight depends on several conditions.
1 line weight
2 lure or bait
3 speed
4 depth fishing
Here we use anywhere from split shot to 1 oz of lead. Most use minnows to spider rig here. Some use jigs tipped with minnows. Our lake is shallow and trolling can mean 18'' to 12' deep. Just remember the heavier lines create more drag and require more lead. Some troll 40 lb test line 12' deep here and require a big sinker . Others may troll 10 lb test 18'' deep and need just a couple of split shot.
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Takeum Jigs