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I would like to try using a GCS proportional thermostat for my incubator this year to better regulate the temps. I wanted to know if it is possible to set the aquarium heater to a level just at the top range of temp for the eggs, and then use the proportional stat to do the regulation. I believe that these heaters work exactly the way that heat tape works, but wanted to ask anyway.
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Stupidity should be Painful!

I would like to try using a GCS proportional thermostat for my incubator this year to better regulate the temps. I wanted to know if it is possible to set the aquarium heater to a level just at the top range of temp for the eggs, and then use the proportional stat to do the regulation. I believe that these heaters work exactly the way that heat tape works, but wanted to ask anyway.

Are you saying that you are going to attempt to use an aquariun thermostat and the aquarium heater for incubating eggs? Or are you going to use the thermastat of an aquirium heater and another heat source for incubation?

You are correct that the aquarium heater works by heating a metal stip/coil (resistive load) to produce heat when the thermostat setting/load demands. Once the heat is on and the temp rises and the setting is achieved, the heater turns off -- or - in the case of a proporational controller, varies the power to the heater to better maintain the temperature at the setting. If you can power a heat tape that is operating at the same voltage as the aquarium heater element, then you are all set...

If you are going to try and use a aquarium heater for heating air directly. be careful. The heat output for a standard aquarium heater is higher than what is needed for air - the heat capacity of water is much, much higher, therefore the heat output of an aquarium heater is greater than that of heat tape. The glass will hold the heat in too much and two things may/will happen - the glass will break or the heating element will burn out. They are not desgined to be used in air. Again, glass tube type Aquarium heaters need the water around them to keep the heater 'cooled' so that neither of these two things happen...

If I'm way off base, let me know.....

I forgot to unplug my aguarium heater after draining the water, within a hour the glass blew apart. They need the water to keep them cool.

Just my $0.02 worth.

John Lian

The way I do it is as follows.

10 gal fish tank with approx. 6-8 in of water.
Bricks stacked in such a way as to hold the egg box above the waterline. (bricks act as a temperature capacitor, helping the fluctuations caused by the on/off control)
The aquarium heater heats the water to whatever temp I need to maintain 82-84 in the eggbox.

The reason I asked was because the aquarium heaters built in thermostat (on/off) is not as accurate as I would like. So if I were to set the aquarium heater to a setting that would heat the water to no more than 85 in the box, and then unplugged the heater from the 110 power and used a helix/gcs/or any proportional thermostat to controlthe power to the heater, what essentially I would be doing is having proportional control with a safety cut off.

this may sound like overkill, but im the type who sleeps better at night knowing I have temperature control with a small fluctuation range.

I hope this made sense being I have a tendancy to babble on.
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Stupidity should be Painful!

Now it is clear what your set up is. Sounds neat...

The idea of having a proportional control regulate the aquarium heater will likely give you a smaller variation in air temp in the "incubator" (or is that incubariun or a aquabator!?!?!?) as long as the proportional setting (called reset and rate) are appropriate. What is appropriate? That depends on the the load needed, variation of that load and the capacity of the heat source. If the load is stable (your set up and use would be considered a stable load) then any reset or rate setting is OK. Problems can occur when the reset/rate over compensate a sudden change in the load making the overshot the setpoint. That is countered by the heat capacitor you have in the bricks though so what you have should be better. The one thing to suggest is when you add water, have its temp roughly the same temp as the water in the tank.....

Without babbling too much, what were the air temperature swings that you saw with the aquarium heater on/off controller running? With the bricks acting as heat sink/source it shouldn't have been too much....

I'm not sure what you mean by "resistive loads" but we use an aquarium heater for our incubator. (We also have fish, and had the stuff on hand).
Basically I have a small aquarium filled with water, complete with filter (no filtration matter, just used for water circulation) and heater. In the tank is a mound of gravel sufficient that the large bowl we use to keep the eggs in rests on the gravel with it's rim well above water level). The bowl is then filled with moist vermiculite and eggs (and a couple thermometers just to keep an eye on the temperature, though so far this hasn't been a problem). Lid with air holes over all to keep humidity up (though when the eggs get ready to hatch I change the lid arrangement so the babies can't somehow get out of the bowl and drown).
Corinne
dragonfly@w-link.net