I have one that I never use as I replaced it with a reptile heater. I used it with a tub that was about the same height as my wort level and had about 2" of space on the sides. I got it up to 90. It’s 50w stick heater. I coupled it with a temp controller and thermowell.
Yeah, I did it for years before I got a freezer. IIRC, it was either a 60 or 100 W heater. I’ll check the next time I head out to the brewery. Worked really well, although it does take some monitoring. Another thing that helped me was to put the heater on a timer so it only came on at the coldest times of day. That will depend on your local weather, though.
I use an Igloo cooler water bath with a heavy duty aquarium heater. Works like a charm. Last weekend, when the temps were single digits, I was fermenting at 70F in my unheated garage.
The one time I used one was when I fermented 3724 @ 90F for the first time, after realizing my fermwrap was toast. I wish I could find the heater - don’t remember the wattage, but it was a heavy duty. It was summer and I put the fermenter in a plastic tote of 90F water, in an upstairs room with the AC vents shut - so the room temp was pretty steady ~ 80F. I put a sleeping bag over the top of the tote with the bucket to insulate. And it worked really well with that setup. I checked temps a couple times a day and it stayed between 90-93F. I didn’t ramp given these temps, but the 3724 finished @ 1.002 in 12 days.
What sort of tub are you all using to hold the warm water bath?
I’ve got my better bottle in a metal wash tub (like you would put a keg in) with warm water and my new aquarium heater.
I have a smaller plastic tub that would work, too. It’s deeper and holds less water, but I’m concerned because the heating element would be approximately 1/4 inch from the side of the BB.
I have an Igloo Ice Cube. I cut a hole in the top and a carboy fits nicely. I use it with a 50w aquarium heater to warm things up and frozen water bottles to cool things down.