Here are the measures I've taken to create a gradient in my 20 gallon. I know the air doesn't have to be as warm b/c I have the UTH, but I am worried that soon in winter, the cool 2/3 will be dropping down to 70 F.
* 8W UTH under L side with Hydrofarm thermostat set to 90 F (measured on top of glass)
* 50W night heat lamp on L side as well
* R side 2/3 covered in plastic wrap
* Cardboard covered on 3 sides
On the hot L side 1/3, air temps are 78-85 (85 on top of the bowl directly under, 78 at the cool edge of hot area). But on the cool side, temp 73 (expected to be lower in winter).
I was hoping the heat from the 50W would spread out more through the tank, but that doesn't seem to really be happening. Do I need another weak heat lamp on the other side of the tank? Or maybe a weak bulb that runs down the center?
(In pic, hide soon to be replaced with something heavier)
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