With D-47, I try to keep it below 70. Basement furnace room that stays around 70-72 during the year. Secondary sits in a rope tub with about 6-8 inches of water. I use frozen water bottles that I swap out in the morning and evening during fermentation. I also have a damp tshirt on the carboy that I keep wet. I think I'm usually keeping it at 65-68. I bought an $80 standup freezer off craigslist and just recently received my aquarium temp controller, so my fermentation temps should stabilize in the near future.