Good luck with the old fluoro. I've tried different brands, different knots, tying them all manner of ways and still find it to be totally unreliable. As to it being invisible
Last season one of our regular anglers recommended Lureflash Mamba to me and swore by the stuff. He reckoned he had
never experienced any breakages once he had discovered the right knot, a seven-turn blood knot!
I saw him a couple of weeks later and he just happened to mention that he had been broken three times
that morning