You should definitely upgrade the tank now since Petco is having their $1 per sale gallon and get a 20L gallon and save yourself some money by doing it now. That size is okay for a couple of years but then you can upgrade to something bigger and better! You can’t use a CHE with a 10gallon bc it won’t allow a proper heat gradient so it’ll be a bit hard to maintain the correct husbandry.
I help anytime I can bc when I first started I was hot mess, everything was wrong and that turned into two expensive vet bills 🤦🏻♀️ because I didn’t have the proper floor and ambient temps.
Step Zero: Ask yourself if you really want a bearded dragon? Did you just get him dumped on you, or what? You just signed up for a lot of work, and maybe you might want to get him homed with someone who does beardies on the regular. Check your local vets for ideas on rehoming.
Step One: Hit a vet and get a diagnosis. If you can't find a herp vet, any basic vet can at least give you some ideas and point you in the direction of an exotic vet.
Step Two: Get Proper Lighting. You'll need a basking light and a UVB light. Good recommendations are here: https://reptifiles.com/bearded-dragon-care/bearded-dragon-temperatures-uvb/ That'll help get the tank temp up and the UVB will help lots. While you're buying lights, get at least one good digital thermometer. https://reptifiles.com/bearded-dragon-care/bearded-dragon-temperatures-uvb/#heating . It's not the best solution, but it'll help while you sort things out.
Step Three: Go grab a box of mixed salad greens. You can dust them with calcium https://www.amazon.com/Flukers-Calcium-Reptile-Supplement-Vitamin/dp/B0002DHPF8/ref=sr_1_1?crid=2JQYRQJGM0PJS&keywords=flukers+calcium&qid=1668758640&s=pet-supplies&sprefix=flukers+%2Cpets%2C214&sr=1-1 later, but just get him some vitamins for a start. Mealworms won't keep him heathy; they're like reptile Cheetos--all taste, no nutrition. At least get some veg in his enclosure so he has the option. Wet the greens a little so he gets some water in him.
Step Four: Yes, by all means feed him some Repti-Boost. https://www.petco.com/shop/en/petcostore/product/flukers-reptaboost-insectavore-and-carnivore-high-amp-boost It will get some vitamins and restoratives into his system fast. It will buy you some time to get some bugs as well as mealworms (you can usually get them from the same places. Or order from these guys: https://dubiaroaches.com/collections/dubia-roaches-for-sale They're incredibly helpful and answer their chat.
Step Five: If this stuff works, you now have a lizard. Clean out that enclosure, put down some paper towels for the moment, and start looking into better food sources.. Taking care of these guys is like taking care of a toddler. But if you put your mind to it, you'll get a great scaly pal who will hangs with you for years to come. Good luck!
I usually use this calcium and d3 power
I try to feed my crickets and waxworms a good diet before I send them to their doom, but I picked up some of these orange cubes to try out since they seem like they're more complete for the crickets and eventually my toad.
Fluker's Calcium Reptile... https://www.amazon.com/dp/B0002DHPF8?ref=ppx_pop_mob_ap_share
Fluker's Reptile Calcium... https://www.amazon.com/dp/B001OROQ8U?ref=ppx_pop_mob_ap_share
Vitamins ! Rep-Cal SRP00300 Herptivite... https://www.amazon.com/dp/B00BS96HRM?ref=ppx_pop_mob_ap_share