To start, the dimensions of the enclosure will be 4'w x 3'h x 2'd and will be sitting on carpet. It will be housing an Argentine Rainbow.

I don't have the tools necessary at my disposal to either cut a large hole in the bottom of the cage or to rout (sp?) out an area for the flex-watt to go. I'm planning on covering the floor in either PVCX or white tileboard and all corners will be sealed with silicone.

I've seen some pictures that have the Flex-watt mounted inside the cage on top of the flooring, but I would worry about the safety of placing a water bowl on top of it. How much air does the flex-watt need to have to avoid overheating? I can 'rout' out a few straight lines to allow some airflow around it, but being a first-time builder, I'm not sure if this would work or not.

Any help that can be given would be MUCH appreciated!!
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currently
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2.0 cats
1.0 horse

fostering
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2.1 kittens

soon to be added
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0.2 cats (temp - 3 months)
1.0 Argentine rainbow boa
1.0 bearded dragon (temp - 3 months)