I used 2# test Nanofill for about 2 years and nothing else. Lost count of how many fish I caught with it to include hundreds and hundreds of smallmouth in the 18-21 inch range. I never tied directly with NanoFil....except just to try it out few times tying directly. It simply has almost no abrasion resistance. I always used a 2# test fluro leader tied to the Nanofill with a simple triple overhand knot...or some call it a surgeons knot. I never had a knot failure doing this. The very few times I did tie directly to Nanofil I used the double palomar knot. It worked fine for me...if a 21 inch Smallie is not going to test the knot I don't know what will. But if you fish rocky reservoirs I strongly suggest always to use some sort of leader.
Regards

