Alternative heat type

This isn't really an alternative fuel source, but rather an alternative way to provide heat to an area.  The foundation of this, is using water to heat an area.  Heating air is very inefficient through traditional ceramic electric heaters, but some people can not build a rocket heater for the thermal mass benefits. This is why I am suggesting that my solution is attempted.  

The idea is to use low watt aquarium heaters to create ambient temperature for a room.  If someone were to lay upon the top of heated tubs of water, I theorize that it would be a cozy night sleep.  

The watts needed is going to vary depending on situation, but I have seen experiment data supporting multiple small heaters.  Someone could use a single large heater, but having a large tank is the issue.   My choice has been the flat rectangular heaters, rather than the glass cylinder ones.  

I am writing this, because I saw a mushroom producer discuss how he was going to use a space heater, and I thought something like this would be a much more energy efficient method.

Currently, this heater is simply being used to stretch em1, with a large 6 dollar stock pot and lid from Walmart, and a milk jug to fit inside.  The 93 degrees should work out well

If you are going to use electricity, then a heat pump is the most efficient one. A heat pump using pipes running underground will also benefit from the thermal mass of the earth.
Also, heating people instead of spaces, saves much energy.

I disagree that it is more efficient, as there are many factors like cost and size of heated area.

Why not use an electric blanket and not have a barrel in your back?

The only way it is more efficient is a little bit of heat overshoot from on the thermostat for the heater and a bit of increased leakage of heat from it.  Otherwise it will take the same number of watt hours to produce the same amount of heat.

Think of yourself as the large amount of mass and an electric blanket as the aquarium heater.

I disagree that it is more efficient, as there are many factors like cost and size of heated area.

Then I may not have understood you. I would only use direct resistors in very low consumption applications, where the cost of any other device can't be amortized in a reasonable time (5 to 10 years is usually fine). If it is a bussiness, then he could study his current cost of electricity, and check whether any investment is worth it.
You may, of course, reduce the costs by reducing the area to be heated, and providing local heat close to where it is needed (such as the heating blanket), is alike to reducing the area.