water dragons and calote

Question
Hello, I have 2 water dragons and one calote all in a 20 gallon high tank.I bought them all from a local pet store. The oldest water dragon is about 7-8 months (5 inches). The younger one (im guessing)is about 3-4 months(about 3 inches). The calote is also about 5.5 inches. They seem to get along fine together. The heat and humidity are pretty much stable at all times. Heat is between 85-90 and humidity is a little above 80.I use both a thermameter and a humidity guage. I use wood chips for the bottom of the tank, a 10 inch water pool. I'm not sure of the brand of light bulb that I have but on the lamp the tag says 120-100 watt R type. I feed them 35 small crickets 3  times a week. The last time they ate was tuesday afternoon.I use Reptocal every time I feed them. The water is changed daily.I also spray them with water very often throughout the day.They do defecate daily. They seem to be quite healthy, the oldest water dragon and calote have shed once already,not the baby water dragon. My baby water dragon keeps his mouth open alot,every where I've read about this had a diferent reason on why they do this. I was wondering if you knew? I was  also wondering if the calote and water dragon could interbreed?I know I need a bigger tank soon, what do you think would be a proper size tank for them(even when they are full grown)? Also I have the air conditioning on in my house, do you think it is ok to let them run around and if so how long can I keep them out of the tank?

Answer
"They seem to get along fine together"...unless you know what to look for, you won't know whether they really are. Cohabiting different genus in the same small tank is a NO NO in my opinion. I am not well versed in Calote husbandry, but different species even coming from the same part of the world may have different habitat preferences, and being confined in spaces where two species can't escape each other may cause stress at the least. I doubt they can reproduce, as they are not even in the same genus.

Without knowing the size and composition of the wood chips, I can't say whether this is good. You might be using cedar chips for all I know. I tend to use and recommend coconut fiber and/with sphagnum moss, which is much less of an impaction or impaling hazard and retains humidity well. You can also use reptile carpet. It is harder to maintain humidity, but easy to clean.

You really have a lot of incomplete information here though. You don't even know whether you are using a UVB lamp or not? What you describe does not sound like one. This sounds like a normal incandescent. You need to get a UVB source, no excuses, and they need to have a separate basking lamp unless you are buying a mercury vapor UVB lamp. I recommend Mega Ray products, found at reptileuv.com.

Sounds like you need more variation in the diet, including trying some veggies. I recommend you research at triciaswaterdragon.com

Using reptocal "every time" you feed them is a problem. This is overuse, and you can cause hypercalcemia, essentially poisoning your lizards by upsetting mineral balance. If you are using a correct diet, the lizards should need supplements much less than this. I supplement about 2 times a month, and I use a varied diet. Once a week is quite sufficient for calcium intake unless you have a gravid female or some hypocalcemic condition occurring.

Is your water dechlorinated? You said changed daily, but not where you got the water.

Are you using a flowing water source?

There are many reasons the young one may have his mouth open. You don't sufficiently describe the circumstances for a reasonable guess. It could be anything from stress to illness.  

For enclosure sizes, you can read this:
http://www.triciaswaterdragon.com/enclosur.htm#Size%20of%20Enclosure