HI. I would try getting the temp up to about 80, to see if that makes a difference. That may encourage your pac to eat more. I only got mine yesterday and I know your not really supposed to try and feed them on the first day (need time to settle in) but I couldn't resist. So in the evening I put some crickets in a small sandwich bag, placed them in the fridge for a few minutes so they weren't as jumpy, dusted with supplement and scooped my pacman from out of the moss (he had buried right down to the bottom of the tank too) and attempted a first feed. He ate like a dozen crickets in one go! and I'm sure would have carried on had I not decided to stop there. Later that evening he was back in the same place of his tank buried right down to the bottom again. I am in the UK where it is pretty cold so I heat my plastic tank with a heatmat attached to one end on the outside of the tank. SO far this is where he likes to be, right next to the side of the tank where the heatmat is. The temp is about 80-81. He's not used his water bowl yet but from past experience I think if you keep their substrate really moist then they don't bother to use the water bowl so much. I sprayed the moss in his tank so much it was practically soaking so this is prob why he won't go near the bowl. Perhaps your black lights are drying the air out a bit. Do you keep his tank really wet or is it a bit dry? Friday I should be getting some nightcrawlers and locusts etc, so I will have another feeding session then, and see how much he eats second time round. I keep saying 'he' - it could be a she - only 2" long at the moment. He/she doesn't have a name yet until I figure out the sex. Let me know how you get on. 
