Well, the first video you linked was mine lol, but the second one doesn't seem to work. They were courting in that video from how I understand it. Mine have tried laying eggs many times after I recorded that, but the water isn't soft enough.
Haha! Whoops! I'm not even sure how I linked that one. I just saw some curious activity from my cpds and I can't find out if they were fighting or spawning. They were basically circling each other. Like chasing each others tails and almost vibrating. I have found mixed reviews about it. I figured this would be the best place to find out