You can keep them in cooler water, but I would start with it around 83 for a couple of weeks then you can slowly lower it to around 80. My main tank stays at 84 degrees with the heaters turned down. The combination of my pump and the top of the tank being closed keeps it warm. The blood parrots will be okay, just make sure you have good agitation or some kind of bubbler because warmer water means less oxygen.