this? https://www.amazon.com/Inkbird-Electronic-Temperature-Germination-Controlling/dp/B07R4XZP3HGet a blue inkbird heater controller for aquariums. It will turn both on and off at the same time when the temperature drops by 1 degree. This prevents 1 heater from doing all the work and burning out prematurely
I wouldn’t worry too much. Bichirs are tough. He will be sluggish, but will survive. He has to be exposed to low temperatures for a good amount of time before it gets bad. A few hours won’t kill him.He’s acclimating in a trash bag to a tank 72.7 degrees. Super stressful. I’ve had him in their for 20 minutes, but want to be 100% sure.
You could probably get away with doing that faster. If I need to make a temp change, I will just turn the heater right to that, probably not recommended but I’ve never had any fish show temp change problems. Same with if I accidentally fill a tank too hot or cold on w/c day.I’ll raise the temp by 1 degree daily until I get to 78