OK, I found my 4 inch sailfin floating in the tub yesterday, the temp got down to about 50F, I got them back up to between 60 and 65.
Do I need to watch for my 8 inch Sailfin to float to the top too?
What is the minimum temp they can survive at?
Remember that we are currently living in an RV and the low temps have been in the teens, they have tank heaters but they are struggling to keep temps up.

I'm pretty sure I read that the lowest they can survive for awhile is around the mid-upper 60s, at lowest. So it might be a bit dangerous for them at 65. I'd put a warm blanket around the tank to get a tiny bit of insulation, and to make them relaxed. Being an RV so bumpy and all.