On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard of
them
before. How efficient are they? I'm looking for any idea that might
work.

Eventually, we're installing some solar panels to run anything we might
need in the green house, but right now it's all on the grid to the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the fish.
If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

--
Maggie