Originally Posted by Nagorg
I'm not sure that aquarium heater should be hanging out in the open air. They are desiged to heat water so it's expected to be in water. The glass tube may crack unless you stick it in a jug of water or something like that.
EDIT: I think I'm now readng that the heater is in water inside the cooler.. If so, cool!
Yeah, put your carboy in the cooler, Fill it with Water
so the carboy is submerged and then put your aquarium heater in there hooked up to the digital temp controller and put the lid on.
If you need to warm up your fermentation the heater will warm the water around the carboy and in return will warm up your fermentation. If you need to cool down your fermentation then just throw a frozen water bottle in the cooler and it will cool down the water and cool down your carboy core temp.
I have found with this chamber, or any other chamber you may build from an old fridge or chest freezer, that you will notice a great increase in the overall outcome of your beer.