GTP Husbandry

Husbandry
Caring for green tree pythons is far easier than most people think. The animals require consistent temperatures, adequate hydration, clean environments, proper caging, and moderate attention.
All of these are covered in detail below.

Temperature
This is one of the more critical and easily maintained aspects of "chondro" husbandry. The keys to properly maintaining heat are a stable room environment, adequately sized heater, thermally efficient caging, and a consistent and reliable thermostat. In my opinion, many people overlook the stable room aspect of heating their cages. Without a stable environment, your cage habitat is unpredictable at best and could harm your animal if your room has large swings in temps. Retailers commonly suggest heaters that are too small for your cage. Problems can be avoided by purchasing your heater from Bob at Pro-Products. He offers the best radiant heat panels on the market and stands behind every last panel he sells. If you are looking to heat a rack, simply make sure the company making the rack is using 11" flex watt on the rear wall or inside rear panel of the rack system.
Thermally efficient caging that is safe for your animal (food-contact safe) is a different problem all together. Most cage makers are using expanded PVC to build both racks and cages. This material is proven to release toxic gases that will in the long term harm your animals. I recommend seeking a cage maker who uses HDPE or Acrylic. Both materials are thermally efficient and both are food-contact safe and will not release any harmful chemicals. Wooden cages are also thermally efficient but are not practical for green tree pythons as they will rot in time with the exposure to water and relative humidity. Even some of the nicer units I have seen—made out of wood and sealed by a plastic laminate and silicone—will eventually need replacing. In my opinion it makes the best sense to spend your money once and have a cage that will outlast you and your collection.
A couple of other notes on plastic cages: There are thinner-walled HDPE cages on the market that are moulded and they are not as efficient as they could be because of the thinner walls. If you're looking at HDPE as a caging material, make sure it is 3/8" to 1/2"thick. Acrylic cages are also thin-walled but far more efficient at 1/4 thicknesses than are glass and HDPE. So acrylic is my personal choice for my caging material.
Thermostats are the brains of the operation. They need to be consistent, meaning trustworthy. There are many thermostats being marketed to the herp community. Most will do the job reasonably well, but they can be a bit more unreliable than you may think. I personally use the Johnson Controls A419 unit. It is manufactured by a large company with lots of funds for R&D. It is also not solely made and marketed to the herp community. It can handle loads far beyond those required to run any normal chondro cage, is easy to set and read, offers a night drop feature, and is inexpensive enough to allow keepers to use a stat on every cage they own.
We have covered most of the basics. Now we'll look at how much heat to provide. I have tried a number of temperatures, and both 24-hour heat and 12-hour heat with a night drop. What I have settled on is a 12-hour light cycle and a 14-hour heat cycle. That means the heat comes on with the lights and cuts out two hours after the lights cut out. I arrived at this after looking at typical summer days and noticing how long the heat of the day sticks around even after the sun goes down. As for temps, I provide a daily basking spot in the 88 to 90 degree range with a gradient to 82 to 84 degrees in the coolest location of the cage. When my night time drop kicks in the cages maintain a gradient from 82 to 78, 82 being of course in the basking area and 78 in the coolest location in the cage. Regardless of what anyone else tells you, the above system works. I have tried and failed with every other system commonly stated as functional on the Net.
It seems the ranges you offer can be simply broken down to average temps throughout every 24 hour cycle. I personally target 84 to 82 as an average temp for normal maintenance

This seems to be the root cause of frustration for keepers of this species, as the snakes' hydration level is tied to the relative humidity of the cage, and is affected by their metabolic rate/cage temps. In trying to understand how to keep your animals hydrated and healthy, you'll find that there are a ton of techniques including foggers, misting, not misting, and so on. Let's get this out of the way: There is no wrong way of keeping your animals hydrated! But there are extremes to both sides of the spectrum that will land your animal at the vet or dead.
I personally prefer misting or spraying my animals because they would naturally get water falling on them in the wild via rain. Misting is a bit more complicated than just spraying the animals down once a day. You do it on a schedule that works with your life style. Over-misting is extremely bad for these snakes. What misting is intended to do is raise the relative humidity and make water available for the animal in a natural way, like they would receive in the wild. The water that is left over on the animals' perches and cage is readily consumed, more so than from a water bowl. The problem with misting is it can and will create a dangerous cage environment for your animals if overdone. The easiest way to find the correct balance is to track the amount of time the cage stays damp. Contrary to much of the info you'll find on the Web, chondros do not need constantly damp cages. In fact, cages that are not allowed to completely dry out are the root cause for illness in this species—often resulting in a respiratory infection from any number of opportunistic bacteria commonly found in and on the animals. These bacteria take hold and create illness as an animal's immune system is compromised by the high levels of bacterial growing in the damp cages.
A good misting schedule allows all your cages to dry out completely for 12 hours or so. Aspects of the cage that affect the drying time are substrate, ventilation, and outside room environment. Again, do not fall prey to the misinformation on the Net that this species requires high relative humidity to stay hydrated. Dry cages will do your animals far more good then you'll ever know. I personally spray my collection with an automatic system once a day; I use no substrate at all, and have all the cages set up with drains so all the extra water exits the cage. I spray my animals in the evening about an hour before the lights cut out and the animals become active and move around. My cages stay damp for right about 4 to 6 hours after the system cycles. In that timeframe my relative humidity levels reach 85% to 90%, with dew point temps in the 75 degree + range. After that my cages RH% falls to match the room which is most often in the 35% to 45% range for the next 18 to 20 hours. I get perfect sheds from my collection about 95% of the time; exceptions are random and not based on anything I can put my finger on. That said, I do not have animals that get completely stuck sheds either. The 5% of the time when an animal has a shedding problem, it's a piece of skin stuck to the head or neck, or a couple tail tips from time to time.
Now, I'll discuss how to deal with pre-shed animals in tubs or cages without drains.
My protocols are simple, and what I am about to explain is how my neonates are kept in 6qt tubs.
I use the same premise of needing a dry cycle as I do with the adults, so again misting some tubs and tracking the average drying time is a huge help in training yourself how much is to much.
I spray my neonates in the morning and shoot for having dry tubs in 4 to 6 hours. This works well for me for all the animals except those in shed. What I have worked out is opaque animals get sprayed again in the evening but only the animal. I use a shift tub and concentrate the water on the animal and then place it back into it's dry tub. This does two things: It allows the animal to drink from it's body and allows the leftover water to soak in. I have not had a neonate have a single issue with shedding in close to a decade with this protocol. This system would also work well for any animals in cages or tubs while doing though a shed cycle. If an animal appears mildly dehydrated in the morning I'll give it a quick spray down with a hose. Again, you can see one of the benefits of having drains. Animals in larger cages with or without removable perches should just be sprayed while in the cage but without spraying the cage itself. This system will also work well if you spray in the evening; just reverse the process.
Last thought/clarification, this species will do well without a humid cage as long as you keep it hydrated. Dry cages do not cause bad shed. Dehydrated animals have bad sheds.

I attack cage hygiene with common sense, considering the conditions in nature and applying them to the captive environment.
First let's look at air quality. In the wild this species would not be exposed to stagnant damp conditions; the air they breath is constantly cleaned by the surrounding flora, sunlight, ozone, and so on. Now, not all of these aspects can be incorporated into the captive environment due the expense and difficulty in controlling and balancing all factors. The best way to ensure high air quality within the cages is to provide a slow and steady air flow which is created by proper vent locations. Once an animal defecates the bacterial levels skyrocket. Most pathogens common to these animal divide/reproduce at alarming rates. So prompt removal of feces and cage cleaning is vital.
Next, let's look at available water sources. In the wild these animals do go to the ground, and I am sure they consume water while there if they come across it. But while they do consume small amounts of aged water, the majority of the water they take in is fresh rain water. I have had conversations with several people who have been in this species's natural environment several times. They tell me it rains daily in most locations, with showers or storms heavy enough to penetrate the canopy--ensuring the snakes get wet or at the very least come in contact and consume fresh running or collected water with out leaving the safety of the canopy. This is a driving force for a large part of my caging set up and my use of an automatic misting system. It is also the reason I obsess over keeping fresh clean water in their water bowls and keeping the bowls themselves from getting foul.
I tend to change water about two or three times a week and replace the water bowls completely each week, or when the animals defecate or drop urates into the bowls.
The last critical and most confusing aspect of caging is substrate. I personally do not think you should use substrate with this species. I can understand why keepers like the natural look it provides with in the cages. But substrate is absorbent and retains fluids. This prolongs the period during which bacteria can generate at alarming rates, leading to dangerous levels of pathogens and poor air quality. Of course, some substrates such as butchers paper and newspaper are better because they dry faster, and there for do limit bacteria levels. Mulch and moss, in my opinion, should never be used with this species; both of these substrates can and will stay wet enough to allow bacterial and fungal pathogens to generate at high rate for days at a time. Add in spraying the cage and animal to keep the animals hydrated, and all the fluid they release with urates and feces, and you are officially creating a petri dish in the bottom of your cages. As the poor conditions slowly wear down the animal's immune system, some pathogen will likely take hold and cause illness.
Consider that this species is rarely down low near the jungle floor. Other than while hunting, when they may be feet above the ground, they reside the majority of their life high above in the forest canopy. If you where to test the air quality and pathogen levels at ground level and, say, 15 feet off the jungle floor, it would become clear why substrate is dangerous in cages and truly not needed by the animals at all.

Green three pythons come from a natural environment that offers them warm to hot temps during the day, moderate temps at night, lots of fresh water in the form of rain, great air quality, and endless perching locations.
Our cages should do the same. So, cages that can maintain heat efficiently both day and night, resist damage and rot from spraying, and offer plenty of perching locations through out the thermal gradient are ideal. Wooden cages are less ideal, as they will rot and have a shorter life span than plastics. While plastics are by far the way to go, not all plastics are created equal. As mentioned previously, some plastics are known to leach and or outgas toxins that will cause long term health issues in the animals' respiratory systems and internal organs. I personally prefer Acrylic, but honestly any food grade plastic such as HDPE, LDPE, HDPP, LDPP, or even Acetron GP an Acetal copolymer are options. All the mentioned plastics are FDA approved for food contact, and do not absorb water or leach and or outgas toxins.The good plastics are more expensive, but having healthy animals is of course worth the extra investment.
Also ideal: Good ventilation that is adjustable and quality radiant heat panels or some other stable radiant heat source.
Below are images of my personal cages, which I designed these to meet all the criteria covered above.
These cages are functioning flawlessly.

You'll notice lots of ventilation, drains, and a mist system. You'll also see no lights are in the cages; I use clear tops and supply lighting via room lighting only. Remember, this species is a canopy dweller, so the majority of light it gets in the wild is filtered/subdued by the foliage above. Not having any electric in the cage just make my cleaning easier, seeing I do not have to watch out for an RHP while rinsing the cages with the hose. You'll also see there is not visible heat in the cages. The heat is supplied with 11" flexwatt in a double rear wall design.
If you have any questions please feel free to contact me.

Green tree pythons are shy animals that prefer not being disturbed on a regular basis. While you will need to check them daily, I do not subscribe to handling unless needed.
Daily inspections should be done while spraying or while the lights are on and the animal is resting. You don't need to de-perch the animal or remove the perch from the cage. Just inspect the animal's perching posture, check temps, inspect the cage for fecal matter and or urates, and freshen up the water bowl. If your cages are designed similar to mine, all this (minus freshening the water bowl and or spraying) can be done without opening the cage. I know that sounds too easy, right? But as I said green tree pythons are shy, and prefer not even to see you unless you're offering them a mouse. Getting good at reading your animals' posture and other chondo signals takes some time but is well worth learning, in order to lighten the stress load our husbandry protocols put on them.
To wrap up this section, green tree pythons are an amazing species to work with, and all the myths of being difficult to keep are false. With the right balance of protocols, this species will thrive under your care. In return, the animals will reward you with great highs—so good they should probably be illegal!
Enjoy!