Fluoro keeps breaking at knot

I used to have this problem a lot. Once I switched to the improved clinch knot it solved the problem for me. One of the keys to knots is a simple one. You have to tie a good clean knot. If you get line overlapping or the knot doesn't cinch up nice and tight, retie the knot before you fish. It doesn't hurt to practice tying knots. I also test my knot a lot during the day. I use a simple test. I wrap the line around one hand and hold the lure firmly in the other and pull hard. If there is a problem with the knot or an abrasion the line will break in your hands and prevent a failure during fishing. A lot of things can impact a knot during fishing that has nothing to do with the knot. Wood, rock, sand, gravel and muscles will all wear on a knot. Its so important to constantly check you line and knot often. Especially if you haven't caught a fish for a while. You also want to look at your hook. Sometimes the line can get caught in the part of the hook eye where the metal is bent around. There are some sharp edges here that can cause a failure unrelated to your knot. VMC makes hooks that have this are welded smooth so there are no edges. I have also settled on Gamma flouro. It has proven to be the toughest line out there for abrasion in my fishing. You are tying the right knots. I hope these tips help you get through this and good luck on your next trip.