Does the magic knot work?
The magic knot is a great way to join yarn. It’s secure and it’s another way to avoid having to weave in ends. Some things to consider about the magic knot: … it can work well for socks but I do suggest you avoid placing the knot under your foot.
Can you change yarn in the middle of a row?
To join new yarn in the middle of a row, when about 36 inches of the old yarn remains, work several more stitches with the old yarn, working the stitches over the end of new yarn (shown in double crochet). Then change yarns in stitch as previously explained.