Cool side still too cold. Do I also need to weakly heat it?

[jplehmann]

If it were me I would want more heat.

It looks like your using a lamp stand. If so, you can use the lamp fixture spring clamp and hook that to the lamp stand so the lamp could be adjusted to a different angle. This way you cold point the lamp more toward the center of the tank to deliver more heat to the cool side. Doing this may allow you to use a larger watt bulb since the hot spot created by the bulb will now be farther away making it cooler.

Another thing I think of is switching from the blue bulb to a red. I like the look of the blue night bulbs too but they don't deliver the same heat it seems as a red one.

Good idea, I thought of angling it this morning but had not tried very hard yet. I did NOT think of bumping up the wattage from 50W to 100W which is what I can try, per your idea of hotter bulb. I was shying away from red b/c don't you not want to use those at night (and I need a 24h solution).

I would also put cardboard on top of the plastic wrap to insulate the top which should trap some heat as well.

Good point, I thought of this this morning and it was good for 1 degree on the far side.

- - - Updated - - -

Agreed the red bulbs are more intense and will provide hotter temps. Also you could think about moving the bulb towards the center of the hab to provide that heat more evenly if you are trying to up the ambient temp.

It seems like you have all the bases basically covered... but it would go a long way towards the heat retention of your set up if you have some substance in your tank. Newspaper Styrofoam and a wire metal bin? don't really make up any substance.

At petsmart you can find earthenware hide and water bowl, the grey or tan ones. They will absorb the heat provided and hold onto it. Aspen will keep the heat away from the glass bottom and inside the tank.

Great point about mass for heat retention. This could be my primary issue at this point.