I assumed my tank temp would be a few degrees above the ambient room temp as well. This leads me to believe the sketchy zoo-med analog temp/humidity gauge I using is garbage. Any recommendations to a decent digital setup ?
Like everyone else has already said, buddy, just shit-can that instrument, and don't worry about replacing it. Save your money for something important. I'd say "temp gun" but you've already got that. Good start, I live by my temp gun. I've got another possible use for your money, which I'll mention it at the end here.
Anyway, I'm thinking the one way you could have a "cold viv" would be via a combination of 1) keeping a super-dry, not-too-cold house, 2) using lighting that provides no heat, and 3) having amazing viv ventilation. Like, Euro-style front vent, with full screen top. So you could have huge evaporative cooling. But that couldn't go on too long unless you were constantly replacing all the lost water. (I'm familiar with this situation, since most of it describes my background situation and keeping setup.) Are you adding a lot of water, but not having to empty drain buckets, ever?
If so, describing my setup could offer some insight. I happen to keep stuff that likes summer days about 75-78F, and nights dropping about 10 degrees. And fairly humid - say 50-70%, with high ventilation.
- The nighttime low is what my basement tends toward in summer anyway - perfect, no struggles, hooray.
- The way I get the daytime highs is a combination of 1) an oil-filled space heater (a DeLonghi with built-in timer and rheostat, which is plugged into a redundant thermostat so I don't get runaway heating if the built-in fails) and 2) my viv lighting, which is a mix of LEDs and CFLs; the latter being my overhead heat source. The CFLs probably give about a 2-3 degree F bump. The space heater is set to heat to 75F between 10 AM and 3 PM, and otherwise just shut off. The lights run 7 AM to 7 PM, so they smooth out the ramps up and down from ambient, plus give a little bitty boost beyond the heater setting in "the heat of the day" (such as it is).
Anyway, hopefully this gives you something to chew on. If you really only need to bump up a few degrees in the day I'd suggest some CFLs. If it's a 24/7 deal I'd suggest an oil-filled radiant space heater (I think they're safer than the fan jobs; I know
they're quieter). DeLonghi has lots of models, some are pretty small. I've had one of the taller ones for a long time now, and - after "fighting" with my wife over it; she kept grabbing it for the laundry room, which is next to the herp room in the basement - I recently got her this one, which apparently is called the Bambino (I didn't know that; it's cute, huh? ha ha):
It has no problem
, on a very low setting, heating a 12'*14', otherwise well-insulated (ceiling and walls) basement room, with a big cold window and a linoleum-on-concrete floor. If you need a nice little space heater, you wouldn't be bummed to get this one.