# Glass Top on Vivarium Cracks under Heat Lamp



## Ebowww (Jun 25, 2016)

Have had dart frogs for almost 4 years now, and never run into this problem. Now in the last 4 weeks have had 2 glass tops crack due to what I have to believe is the heat lamp. The heat lamp has sat 1" (bulbs being 2-3") above the tank the entire time, and tank has never gotten above 78. I have a dual dome, with each bulb being 40W (only one is on at a time, for 12 hours). I moved to a 20 G Tank in late 2017.

First top was 1/8" thick, and it was the one I put on in late 2017 (so had been through at least 1 winter). Cracked the glass in 2 clean pieces right under the heat lamp.

Second top I upped the thickness to 1/4". Cracked after the 2nd night (last night) in the same pattern, right under the bulb, except this time there was a 3rd piece right under the bulb that looks like it was about to fall in. 3rd piece wasn't tiny either, it was 3x3". Ended up doing the duct tape trick to make sure it didn't fall in as I was removing this top, but still nerve-racking.

Questions for the experts:

1. Obviously, this heat lamp is no longer working with my glass tops. Should I even attempt to go tempered glass, or just nix this dual dome and look to alternatives.

2. I've read some bad things about heat pads, are there any other alternatives to heat lamps that would heat a tank at the same level? The tank is in a room that gets pretty cold at night.

3. Sanity check on another potential solution: If I up the wattage of the bulb and dome to 100, and move the dome to 5-6 inches away from the tank, will that provide enough circulation to prevent cracks?

Thanks!


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## Socratic Monologue (Apr 7, 2018)

The obvious, best solution is to move the viv into a room that is the proper temp for dart frogs. 

Presumably there is some ventilation on the top of the viv; could you locate the heat lamps above that screened area? This would solve the glass cracking problem. You might consider using a physically smaller lamp for heating -- for these tight spots I like the 25w halogen pucks that are designed for under-cabinet use.

Google tells me tempered glass is pretty heat resistant -- 'up to 470F' -- but I don't know if it can handle localized heating much better than regular glass. At least you don't cut your hands off on the broken pieces.

Ceramic glass would certainly handle any temps an incandescent lamp could produce.


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## tropfrog (Sep 6, 2018)

I use a heat pad mounted to the side of my tank. It has worked like that for 2 years now without any cracks.

BR
Magnus


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## varanoid (Jan 21, 2011)

Something doesn't quite add up to me. I have never had a glass top crack or break from the heat emitted from a heat lamp (I've used heat lamps in the past for reptiles, never dart frogs). Even when placed directly on the top of the glass.

Do you have cats? Most of the time glass cracks is from physical trauma. The only other time that I have seen it crack is from a sudden temperature change, like taking a piping hot glass out of the dishwasher and pouring ice water into it immediately. 


Socratic's suggestion is the easiest solution. Keep your tank in a room with appropriate room temperature heat where supplemental heat will not be required.


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## Tanks (Jan 14, 2019)

^^ That was my first thought too. I’m not sure of your location but it’s been a crazy cold winter here in MI. The heat lamp for my ball python tank heats up the metal screen very fast..within a minute. I would guess the glass would have to be pretty cold for this to happen though..too cold for amphibians anyway. 

If you can’t move the tank location, a space heater might work. 

Heat pads are great if they’re used properly- air flow/ breathing space and a thermostat. They’re supposed to heat up the entire pane of glass, but if the heating pad is on the bottom and there’s standing water on the bottom of the tank it’s more likely to crack the glass, especially if it’s colder water. 

I’ve found that the side of tanks are better for placing heat pads on vivariums, but if the tank wall is covered(insulated) with great stuff foam or foam board, I’m not sure how effective it would be?


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