The deal behind all the tank changes was to see if Casper would live with well...anything. It was all a big nope.
First swaped tanks with Casper and Thor. To see if Casper would tolerate living with any of the catfish, Betsie, or the PTC. Within hours all the fish got moved out. Casper was a methodical relentless ***hat and ended up alone in the planted tank. So I tried Thor and Casper, another nope. Casper didn't start fights but sure finished them. So Thor got moved back in with all the extras and Goldie. By day three Thor was relentlessly chasing her so Goldie went back in with her hubby Casper. That's actually going good. Built her a cave Casper can't get into, so she has a safe hide from his shenanigans.