I usually use Yozuri hybrid which is a copolymer. But lately because of this very clear water, I’ve been using Seagaur InvizX. It has a pretty smooth surface finish, which reduces the friction, (and therefore heat) that is created when cinching the knot. This equates to not as much damage and more strength. It’s also very supple for a 100% fluorocarbon. It does have a little more stretch than I like but overall seems pretty good.