I hate to tell you this, but chain petstores are the single worst place to get advice for animals. You're going to have to make some changes for your babies. My first concern is how long, tip to tip, is this baby? It's unusual for them to sell babies that are past the hatchling stage - most they sell are only a couple weeks old and are absolutely tiny - much too young to be sold.
What type of thermometer did they sell you? You need a digital thermometer with a probe or a temp gun for an accurate basking surface temp. Those stick on strips and dials that most petstores talk new owners into are pretty much worthless. Once you have a good thermometer, measure the temp of the basking surface. That temp needs to be between 110* and 120*F.
The calcisand is very unsanitary and very dangerous to your baby. When wet, including in the dragons intestines, it becomes hard clumps that are similar to concrete. It causes nasty blockages that often lead to death. This forum, and most others, recommend nonparticle substrates - especially for new owners and young dragons. Textured ceramic tiles, nonadhesive shelf liner, reptile carpet, paper towels, and newspaper all make safe substrates.
The pool isn't needed. Most dragons won't drink standing water and the bacteria and humidity from the water in their enclosure can cause health problems. Most of us just soak our dragons for 15 minutes every couple of days. They absorb water through the vent (butt), so they're well hydrated with frequent soaking.
Please don't give him mealworms. They're very fatty, low in nutrition, high in phosphorus (binds calcium), and hard to digest. Stick with crickets, feeder roaches, silkworms, hornworms, or phoenix worms for your baby. Most experienced keepers also avoid the pellet foods or anything that comes pre-made. Those foods tend to be full of preservatives and things that aren't healthy for our babies. All insects should be removed from his enclosure after 15 minutes.
His salad needs some changing. The foods shown in green on this chart will make the healthiest foods. The ones in black are good for an occasional treat. Treats should be given in small amounts no more than once or twice a week.
http://www.beautifuldragons.com/Nutrition.htmlYou didn't mention a UVB light. Do you have one? What brand, rating, and bulb style (florescent tube, coil) is it?
