Personally, for spinning reels I really don't see the need to go higher than 14# Fireline or 15# PowerPro. And on my new an awesome Penn 525 mag, 15# mono. Don't forget a shock leader thats 10# for every oz of lead you're throwing. Length of shock leader should be about 2 rod lengths plus a few wraps around the spool. Also remember to tighten down the drag on the spinner prior to casting and then re-set it before placing it in the sand spike.