the best way to do it involves fish tank bubblers, but in my opinion the whole incubation thing is really overblown. once you have your setup in place, you can always keep enough jars colonizing to suit your needs. if time in the canning jars is really at a premium, then a good incubation setup is shroomgods, where a large flat rubbermaid container is filled with water and a fairly high watt submersible fishtank heater is placed in it and set to the desired temp, then the cover is placed on the tank and you put the jars on top of the cover, and put something like a blanket or a plastic cover or something over the entire thing. this isn't really necessary for most people, however.

--Nyar15

When I first got a heat pad, I cooked a bunch of jars. I haven't been too keen to use it again yet. But I'm thinking of converting a closet and would use it on a shelf for colonizing jars.

redfuzz

Thanks everyone