I need to know if my Water Dragon Skits is sick.

Question
Hello;
I just wanted to start off by saying, I really don't know alot about lizards, all I know is what I've been told about the ones in my house...My boyfriend has a bunch of different kinds throughout the house. We have a Bearded Dragon and hes a couple years old hes a great lizard hes actually one I touch lol.A Golden Gecko and a Tokay Gecko in a very large tank together, and yes we know they arent supposed to be together but when we bought the Tokay the owner of the pet shop said it was ok to put them in the same tank because its such a large one. We also have an Iguana hes the newest addition, I personally like Iguanas but this one doesnt like me for some reason, everytime I come near the cage he/she freaks out and scurries around the tank. And the last two we have is a Green Anole, and a Chinese Water dragon, their in the same tank together and get along great. The question I have is about our Water Dragon(Skits) he/she is that old maybe 6-9 months just a baby, and i've noticed lately that he doesnt seem to be as active as usual, and he also leaves his mouth open alot and inside of his mouth it looks very dark almost like hes got dirt stuck inside and he just looks very sick to me. His tank is a 20 gallon and he can't be more than a foot long(nose to end of tail) He eats crickets, has treats sometimes not very often mostly of greens like lettuce or shaved carrots. The crickets are covered in calcium powder before put in the tank. So I dont see why he has such an unhealthy look to him, the only thing we can think of is that because where we live the temperature is dropping it about to be winter here it even snowed today. And we think that his tank it too close to the floor, or his light wasnt good enough. Today when we went to the rep. store we bought a new light for him so now he has two on the tank he seems to have alot more energy and hes been digging at the bottom of the tank today. He still looks a little off but like I said hes gotten a little more perky since the new light is on him. If you can think of anything else were missing please email me and let me know, I really dont want any of the lizards to die even though none of them really like me except Skits and the Bearded Dragon. Thanks for listening/reading lol.

Answer
Hey Courtney, you need to take Skits to the nearest vet as soon as you possibly can. It sounds to me like he/she has RI (Respiratory Infection) The mouth wide open breathing is what makes me think this. It is fatal if not caught early enough so don't waste any time. I suggest NOT mixing ANY two different species of Reptiles together. No matter what. The Water Dragon can kill the anole. There is a large difference in size and a sick animal needs his own home. I do NOT think that Skits is sick because of anything you did. Pet stores aren't really good with the husbandry on health. Here is some more information on RI if you don't think thats what is wrong let me know. http://www.triciaswaterdragon.com/ailments.htm#respiratory
I hope that its nothing serious. Let me know how it goes. If you need help finding a vet let me know I know of a couple sites with recommended vets. I hope everything is ok, please let me know how it goes. Good luck to you and Skits!!!!