I am building a fermenting box on the cheap, I have the STC-1000, and an insulated box. What is the best heat source, pads, belts, lamps, fish tank heaters ???? I am using 5 litre glass carboys..and all grain. Marty..

  • Can you explain how you want this to work? – Bolwerk Jun 30 '16 at 16:31
  • Yes, I have an ambient here at the moment of 1deg C to 16deg C, I have the box and the controller, as said, I am doing this as cheap as possible, so I just need a heat source, that is low wattage and cheap. So far I have come up with a reptile heating cord at 15 watt, and 2 m long for $20. Just looking for other ideas as I have no way of knowing if my idea will do the job. – Marty Jun 30 '16 at 19:34

I use a 1500w space heater with a fan.

Aim it at the wall or have a shield for your carboys. I've found if warm air hits the carboy directly it will kinda bake on krausen in that area.

To prevent the heater from comming on right after the freezer cycles.

  1. Put your prob in a thermo well in the fermentor, or a large glass bottle of water.

  2. Set the temp variance to 1-2° not the 0.1°

  3. Set the delay to 1-2 minutes.

  4. Don't aim the heater at the temp prob. Put it in a place that gets a good ambient if it's not in the wort.


Your best bet is a Pad or belt. and as EZ stated, thermowell, for the temp sensor in the carboy.

do not use fishtank heaters, those are meant for water heating only and may malfunction, and usually contain a temp control on it.

as looking at your comment too, the heating cord may work too, but it will take longer to get to your desired temp, but will keep it there as long as the settings are correct, and you are not opening the insulated box very often.


I use a reptile heater lamp. It gives off no light and is easy to control.


At an ambient of 16degC you might need to think about cooling too. Fermentation is exothermic so your insulated box could heat up well above ambient. Connecting a fan to the cooling circuit of the STC to draw air into the box would work.

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