Originally Posted by Bombalurina
I would suggest adding in a bunch more plants and decorations to break up his line of sight more. This will hopefully encourage him to claim just one area of the tank of his own and only chase the platys when they go into it.
If that doesn't work, you may have to look at removing him.
He seems to have calmed down a bit already and he's spending a lot of time in the most heavily planted corner, hiding in the back and in the plants themselves. I'll be monitoring the tank closely over the next few days.
I've ordered plants that should be arriving soon that I can use to break his line of sight. The platys honestly seem to care less and are sticking to the opposite side of the tank and the top/front where they are always playing. They're staying away from his corner for the most part.
I do have a hospital/quarantine tank he can stay in for a few more days until I can get a divider in my 10G (my for new cories are almost ready to move into the big tank and complete the school). If I need to separate him, I certainly can.