3 armed baby bearded dragon

I have a 3 legged baby bearded dragon about 8 inches long i adopted from a neighbor. I was wondering how many watt lightbulb should i have in there to keep him warm? right now i have 70. i also notice that he doesnt chase the food and doesnt eat many crickets is it because hes not hot enough? would his missing leg cause him to not chase the food? hes not very active either.

[crabby70]

Feeding baby dragons
You will have to be careful not to overfeed the baby bearded dragons. Overfeeding can put pressure on the lizards nerves and cause paralysis in the rear legs and possibly death. They will need a lot of food, but in smaller frequent meals. Good food will be small crickets, recently molted mealworms, and wax worms. The insects should be gut loaded and coated with vitamin and mineral powder several times a week. A calcium powder should be coated on the insects daily. Be sure to introduce them to vegetables about every other day. The vegetables should be finely chopped and in small quantitiesAn under tank heat pad.

Lighting: Fluorescent full spectrum lighting with UVB
Temperatures: 78-88°F; basking area of 95-100°F; night time temperatures in the 70's