Questions about Heat Tape...

Iv built a new space for my Snake. I built a 48" long 12" high and 14" deep terrarium. I want to do this right the first time, so I have questions about properly heating. I understand that 1/3 of the cage should be the hot area, and I wish to heat that area using heat tape and a thermostat. My terrarium is glass bottomed.. How should I go about doing this?

2 rows of 6" tape? one 12" row?
Herpastat? What are my options??

There are too many options to ever list. I would suggest a herpstat as they have a long term track record and have lead the field in safety options. I would tend to run one piece of heat tape. Either 11 inch flex watt or actually just buy a UTH pre-made. The advantage of remade is it is fully certified over the diy electrical appliances. Where I am diy heaters must be wired by an electrician.

Thank you, Im no stranger to electrical or electronics. Part of my plan was to use a RaspberryPI to monitor and control the heat, light, and humidity of the enclosure.. But that is to come. As for personally wiring up the heating element or device, why would I need an electrician to do so? Im in BC, I just moved here from Ontario, and Iv never herd of that. Other then running the mains conductor from the pole thru to the pannel, Iv wired everything else up in the house from the pannel to the outlets, and building electronic devices.

an 11" x 12" and an additional 3" x 11" patch of flexwatt or generic heat tape was what I was thinking, that would give me the 16" coverage I need for the 1/3 rule. Wired in parallel. Controled by a thermostat of course.

If I'm understanding what you mean, two different sized heat tape strips are going to heat at different rates (and have different capacities). As kitedemon said, I'd just have one strip. At the very least though, if you have two strips wired together, they need to be the same size.

I understand the diferences in the Capacities, and the resisstance, Resistances in Parallel are as follows :

1/R_t=1/R₁+1/R₂+1/R₃ .... thus, the total resistance, is less then the lowest resistance in the circuit. Meaning, that the 3" tape will be working at its optimal, while the 11" strip will be working half of its optimal. I could use multiple strips of the 3" tape, as in, 3 strips, 16" long. Wired in a similar fasion, giving all 3 strips equal Voltage, equal amperage, alowing for equal wattage/heat output.

The controller will monitor, to ensure no over amperage, or excessive draw. Leading to a safer circuit, and less chances of burns and fires. Iv really got my head wrapped around this controller idea... More to fallow.. Watch and shoot!

Sorry I should have been more specific. I run a business from my home and under Canadian law all electrical wiring in a place of business must be done by a certified electrician. In my case because I run a business I must have an electrician wire and certify everything, or I have no insurance and am criminally liable. After Westray this is a very very serious.

The other issue with dual heaters rather than a single larger one is the heat (resistance) over the surface of the element is inconsistent. In theory having two would force this to be (more) even. It will in fact. But there is always that pesky murphy that it is also possible to get two sections of higher resistance to align (by sheer bad luck) and generate a hot spot add some thermal gain and potentially quite a lot hotter than expected. With this in mind I would not use dual strips.

I personally prefer ultratherms to everything. They have a superior construction and are a lower density (resistance) heater and simply do not get over 100ºF. If you add a thermal degradation fuse (switch) to the loop it is seriously safe it simply cannot cause burns no matter what happens to the thermostat.

Flex watt often gets over 110ºF and THG gets hotter still. (they also emphatically state never to disinfect the product, and I personally believe any product from a reptile supplier should be disinfected before use because staff at reptile places have reptiles and somethings can be carried by a human vector)

Two different sizes of heating source run by one controlling device are going to run at different temperatures.
You would need a device that is capable of regulating multiple heat sources.
The math only goes so far.

School me on ultratherm, Im reading up on it now myself. There is an 11" x 17" pad, wich will work just fine for my application. Ill Just need to design my controller..

Have u looked into RHP

RHP? Im a soldier so I can throw ANYTHING into an acronym. lol.