Amphiprion wrote:My opinion..
I think you are overthinking and overdoing things with regards to temperature..
Cubensis Mycelium is quite forgiving, It will colonize jars from above freezing, to 30C.
I would stay away from heat pads/mats and rather use a space heater to heat the entire room that your jars are in. You will get less condensation this way.
I have a small room with a space heater with my jars/bags hanging around 24c-27c. If the temp stays in this range its ideal, but not mandatory for success..
I am a bit concerned about energy costs so I used the small heat pad I already have and not needing to buy an expensive direct heater, which also consumes lot of electricity (kilowatts instead of 10s of watts).
I also use the room for storing various (mostly volatile) chemicals in racks, that's another reason why I am concerned about heating that room... mushrooms occupy just a small part of that storage space.
I recently found this "LightHouse ECOHEAT" heater which is used to to prevent plants from freezing in small spaces like greenhouses - it radiates heat in all directions and seems to be energy efficient:
Anyway, the mycelium seems to do just fine. The only issue is that some jars are hot to touch and some are cold. It's hard to heat them evenly - I know the myc. will withstand wide range of temperatures, but the huge temp. gradient might be a problem (e.g. 15-20 degrees difference from side to side of the same jar) as well as huge day/night temperature differences. So any kind of local space heater will probably be an improvement.
Of course, I don't need to heat it at all, though this will extend colonization time and invite more contamination.