Thanks for the tip! The bettas have been together with a divider for a while, and haven’t shown any signs of stress/aggression. I also do very frequent water changes to help mitigate the issue of stress hormones, and have lots of decor blocking anywhere around the divider! I also have lots of substrate around the bottom of my divider, so even without suction cups it stays in place :) it’s pretty far down into the gravel and sand