Red Planaria Life Cycle/Treatment

[Sleepydoc]

I have not tried leaving it in for several days. But i would be worried that it would kill other types of worms such as bristle worms etc if you did that?

I didn't see any evidence of that, but then most of the time they're hidden away so if they died under a rock I wouldn't have seen them. On a macro level didn't see any evidence of damage to other inhabitants.