A good line is essential when ice fishing. You need a line that will remain limp in the cold, yet stand up to the abuse of scraping along the ice during a fight. I’ve had some great success using Berkley Trilene 100% Fluorocarbon Professional Grade in 8 pound test. The Fluorocarbon is tough and abrasion resistant, yet its low visibility under water is key, especially it seems in ice fishing. Walleyes under the ice are just pickier than they are in warmer water, so the ultra-finesse of the low-vis line can make a big difference in the number of bites you get. I also like using 10 pound test Berkley Nanofil in the Low-Vis Green color, especially when fishing in waters where bigger walleyes are in the mix. But when using the Nanofil, I will add a 3 foot leader of the Fluorocarbon for a stealthier presentation.