heating glass tanks

[rwg]

Well, I switched substrates from "forest bed" which I think is some kind of mulch, to aspen shavings. Figured I may need to recalibrate my rheostat setting so I took some measurements. Admittedly, this was with a crappy thermometer, but here's what I found:

Setup: 40gallon short with snap-on wire lid, and large UTH directly under one end. 2-3 inches of aspen. Plastic aquarium frame leaves app 1/4 inch clearance between UTH and bottom glass surface. UTH is on a rheostat.:

ambient hot side: 75
ambient cold side: 72
ambient outside of tank: 70
ambient inside hot hide: 80
temp hot side under substrate: 110
Note: glass on hot side hot to the touch.

To get the "under subtrate reading, I put the thermometer on the glass on the hot side, and burried it under substrate to normal depth.

I have some thoughts. Either the aspen is so good an insulator that the glass is getting too hot, and the ambient temperature is almost unaffected by the heat source OR glass sucks in general, aspen or no aspen, and I wont get the ambient temperature I want in there using a UTH under a glass tank.

I'm going to turn off the UTH tonight (turned it way down already), and let the floor cool. Then I'm going to switch to a reflector lamp, and do all the same readings to see if a lamp is better for providing the right temps and gradients in a glass aquarium. I'll post my results tomorrow.

For the record, this is a corn snake enclosure.

rg

[BoidKeeper]

I always line the bottom with newspaper and then I lay what ever else I'm using on top that way even if they barry them selves in it they still have the paper between them and the hot glass. Also I never stick the UTH to the glass I just lay it under the tank. This helps with ventalation and temp control.
You may want to get a digital with a max min memory and an out door probe. They are like $20. However avoid Presicion Temp. I've 4 and none have lasted.
Cheers,
Trevor

[rwg]

I did measurements with my reflector lamp last night with the same setup otherwise...here's what I found:

ambient outside tank: 72
cold side ambient: 72
hot side ambient: 80
inside hot hide: 80
hot side under substrate: 78
basking spot: 90 (110)*

* thermometer is black. lower reading was covered with a few bits of substrate, and higher reading was directly in the lamp-light.

Seems a better heating solution than the UTH. Going to get an infrared bulb, and see if it works as well.

Question: Will I get more heat from an infrared bulb than from an incandescent of the same wattage? I would expect so.

rg

[BoidKeeper]

What are you using to measure you temps? What are you putting in the tank? If the room is only 72 during the day what is it going down to at night?
As for the heat lamp question I'd say yes.
Trevor

non-arboreal snake use bottom heat

[rwg]

Originally posted by reverendsterlin
non-arboreal snake use bottom heat

I certainly wont argue with that but I'm wondering how effective bottom heat is in this kind of a setup where the glass is way too hot, and the ambient temperature is still too low. I never really thought of it as a matter of bottom heat vs top heat. Was really only thinking of getting the various ambient readings about right. Does it really make a big difference?

BoidKeeper: I used a crappy dial thermometer. Nightime temps drop maybe only a couple of degrees in the room. I have been using the same UTH settings around the clock, so I suspect the cage ambient temps drop 1 or 2 degrees at most at night.

[BoidKeeper]

Maybe you should try raising the room temp that way you won't have to heat the bottom so much.
Trevor