Yes, try a lower watt bulb or suspend the light if you can. I have to use red bulbs over my cool sides and have them suspended so one bulb is heating two tanks (the cool ends are next to each other).
The 'all in one' dusts are fine to use, adding the pure calcium should be all you need, he will lick it when he needs to! I always keep some in the tanks, just a little bit in a little plastic milk jug top, they do lick it...and track it around, they like to help