Same color joins - opinions please

Hi everyone! New knitter here, working on my first project (a scarf based on the ones from the early Harry Potter movies, from this pattern: A photo is in the first post of this thread, only now I’ve finished the bronze stripe and am almost done with the subsequent blue stripe:

I’ve been ok so far, changed colors several times with no major problems, and now I’m almost done with my first ball of blue yarn. I have enough to finish this stripe, but not enough to get another full stripe done. What do all of you recommend when I reach the next blue stripe–just start a new ball of yarn, or completely use up the first ball and just have a same-color join? I already had to do a same-color join with one of the bronze stripes because the yarn ball became knotted beyond repair and I had to cut it.

It’s not a major deal since it’s knit in the round so all the joins are hidden in the tube, but it seems like whenever I join the stitch right near it is looser than my others.

I don’t know how you’re doing your joins but if you overlap the new and the old strands for one or two sts and then go back later and tug lightly on the free ends before weaving in the ends, there won’t be a hole or any loose sts. For the join you have already, if you again, tighten up the loose st before you weave in the ends, that should take care of the looseness. If you haven’t overlapped yarns, just be sure to cross the old and new yarn tails so you don’t get a hole.
As far as starting a new ball of yarn, it’s up to you. The join is essentially undetectable anyway.
I made a Harry Potter scarf this same way for my niece. Good luck with yours!

I love this braided join because you don’t have to weave in any ends! The ends don’t really matter for your particular project, but for most projects I like to avoid weaving ends as much as possible, I hate doing it.

There are some ways of joining yarn, depending on that kind of yarn you’re using. I personally prefer the russian join whenever doable. If you know the yarn is not gonna last for one more stripe, and you still got a lot of yarn left, I’d go with finish the ball, then join. If the leftoveryarn is not worth mentionning, just pick up another ball.