My temps are lik 79 in both tanks. They are both pretty angry. I do believe that lowering the temps will slow down their matabolism they wont eat as much food and wont be as active. I like them active and growing fast.
Nice Green Terror!! My GT and Oscar seem to get along fine they have been together in the same tank for about 2 years so i think they will remain friends. Your Tank is large enough to keep using your divider or you can plant living plants as a divider to simulate a natural river border perhaps. Good Luck
Green terrors were given that name for a good reason. It isn't uncommon for them to kill oscars twice their mass. The oscar really needs to be much larger to intimidate the terror into submission....usually. Then again every case is a little different.