aquarium heater not working well enough

i have an aquarium heater to keep my brew warm while it's in the secondary fermenter but it doesn't keep the temps at a steady 68deg like i want it. will be 70 during the day and 60 at night. i turn off the heat at night so that's when i need it the most. while its in the primary the heat is left on at night.

is there a better way to do this? i would like to have a consistent temp throughout including when it's bottled. the only thing i can think of is getting an old freezer and putting a heater in it with a controller. if i did that, what would be a good controller to use, price being the biggest factor.

 

Stc 1000, either on Amazon or eBay... you will have to do a bit of building but it's not hard to do at all.

 

STC is nice unit especially if you need to control cooling and heating at the same time. But it doesn't support Fahrenheit, only Celsius.
If you need to control only cooling or heating (as in your case) you can buy cheaper unit and with Fahrenheit support - like this one http://www.ebay.ca/itm/Digital-Temp...stat-58-194-Fahrenheit-W-Sensor-/350947244789

 

Explore insulating the FV (several old coats ,blankets, spare duvet anything just several inches of it) , try to have the brew controlling the temp rather than the environment, you will have to turn the heater down quite a bit.

 

Check the glass of the heater to make sure it's all intact! I had a pin-hole in my old one a while back and it had filled with water. The indicator light was still working as it should and it looked fine at a glance. They also have no earth/ground so I'm not sure how I feel about the whole experience ...

These things should be able to practically boil the beer if left on full power ...

I would definitely agree on adding the STC-1000, aquarium heaters are low enough power than you can run them straight through the internal relay.

 

How large is the bath you have your brew in? What is the wattage on your heater?

 

I have no problems with aquarium heater controlling water temp of 10-12 gallons of water with a 5-6 gallons fermentor in a 20 gallon plastic tub. If you are getting hot spots than changing the thermostat to STC-1000 wont help, you will need to circulate the water.

If you are using a reptile heat matt than maybe it is underpowered or you need to add insulation to the fermentor.

 

I found that setting my tub on a blanket folded up and wrapping the tub in another blanket allowed the aquarium heater to do a much better job.

Especially if the tub is sitting on concrete.

 

You got it Rhumbline you got to have a cosy bottom !

 

it's a 150w heater in 10 gals of water with 2 5gal fermenting vessels. this is all placed on mats with a blanket over the top. I feel the 150w is a little over powered, it's not like it's 30degs inside at night. maybe 50 at the lowest. i think I'm running into problems with the aquarium heater temp controller not being accurate enough.

i can't just put a bunch of blankets on and hope it works, shmbo is already unhappy with the container being there. I could buy a very large cooler possibly but i would want to be sure it works and it might not even be worth the investment.

might get the chest freezer and put it in the garage with the aquarium heater, then if that doesn't work I'll do it with a ceramic heater and STC-1000

 

Ten gallons of water and ten gallons of beer is probably asking too much in temps in the 50's. I do about five and five in the 70's and can get it up into the low 90's barely (Saisons).

How about the chest freezer with an electric blanket inside?

 

Good point but honestly for something like this were a specific temp is set it doesnt really matter? it takes all of 20 seconds to bring a celcius temp converter up on a pc or phone. plus I'm fairly certian someone else who has already tried the one you linked stated it does heating OR cooling and not both at the same time.... unless they redesigned it.
if an aquarium heater cant maintain temps of 10-20 gallons of water then somethings wrong.... what size heater is it?? I have a 150gallon reef tank and it gets down to about 60 at times here and my 300w heater maintains 78degree water temps... the key is circulation... buy a $6-9 aquarium pump at harbor freight. a heater as small as 50w should work for you no problem.

 

The idea of a small pump to circulate will help. 150W is not enough to maintain that 30deg difference to the atmosphere. You need more power. Everyone is jumping on this STC1000 thing but there are internal thermometers on the larger watt units that will get you close enough for what you are trying to do. Remember the STC 1000 is not a PID controller, so even though it cuts power once temps are reached there will be a bit of carry over heating.

 

I don't see how it should be struggling at those temps. The thermostats on mine keep things pretty level, and they're cheap. Are you sure you're temping at the same depth? Mine is usually much warmer at the surface than below. It's not ideal, I need to get working on a circulator and in-fermenter temp probes so I can arduino this thing up.

I suppose I should have my heater at the bottom to get some convection action, come to think.

 

maybe it's the circulation? guess i'll try that

 

Just to update, I moved my heater to the bottom, and I'm getting good circulation without the pump now (which is annoying because a cheap pump is going to arrive tomorrow, but I'll find something to use it for). As of yesterday I have two 5-gallon buckets at peak krausen in the same tub, and the water temp tested 63.2F all over the tub, with inside temp 64.0F on both buckets. Air in room was 52F. Depth didn't change the reading more than 0.2-0.3F in the tub and produced no change in the buckets (which I guess have their own little convection going on inside due to fermentation).

Note that a water bath keeps temperatures closer to ambient because it also conducts fermentation heat away from the fermenters. So even if you have a fancy-pants fridge setup, I say you should really be using a water bath to buffer internal temperature swings.