How do you know if a closed enclosure has enough oxygen.

[Jaxtortoise]

Building a 4 foot long 3 feet wide 2 foot high plywood enclosure. One side has Plexiglas on it. I was going to put a ceramic heat emitter and light inside the enclosure. I wanted to know if it is completely sealed minus a small hole for cords how do I know the red foot is getting enough oxygen. I know when opening the front it lets oxygen in but the rest of the time mostly sealed.

The tortoise lives out side most of the year just inside for probably a month.

 

[Anyfoot]

Building a 4 foot long 3 feet wide 2 foot high plywood enclosure. One side has Plexiglas on it. I was going to put a ceramic heat emitter and light inside the enclosure. I wanted to know if it is completely sealed minus a small hole for cords how do I know the red foot is getting enough oxygen. I know when opening the front it lets oxygen in but the rest of the time mostly sealed.

The tortoise lives out side most of the year just inside for probably a month.

It will be fine, with you opening it a few times every day it will get enough oxygen and any minor gaps for wires or where your plexiglass is will help. If you wanted to you could fit a couple of small vents that can be opened or closed to control temp and humidity. You'll probably end up with them closed though.
CHE is a good option, put it on a thermostat and be sure it's in a ceramic holder, not a plastic one, set it to read 86f under the CHE, in that size enclosure you may be better with it in the middle and Probably a 150watt. Put a hide under the CHE so your tort can't sit directly under it and dry out. Put moist moss in hide too. Also put hides furthest away from heat source so your guy can hide and select the temp he wants.
What light are you going to use?

 

[Anyfoot]

Should have added, don't mess about with any domes for your CHE, all this does is consentrate the heat into one smaller area, without a dome it will spread the heat evenly creating a less harsh ambient temp.

 

[Jaxtortoise]

Thanks for the information. I will have to look at the light when I get home and get back to you. Great idea with the vents. Thanks

 

[Jaxtortoise]

Sorry for delay Christmas came fast. I have a thermostat and the light I have is a zoo med 75w basking light. Not sure if that will be to much along with the CHE inside the enclouser. I might just do a regular light or try the basking and monitor it since the tortoise lives outside 90% of the year. Currently in baby pool with both but humidity is the problem. Thanks agian for all your help.