I don't think it's MEAN either to use a breeder net if that's what your options are. I put my platy in one right after I saw a little fry in the tank, she had all of them and I quickly moved her back out. I doubt it was More stressful then the open tank. My other two platies were chasing her around like crazy. I plan to move her to a fry tank next time I want to keep them, but that wasn't an option last time.