I really hate to see posts like this. Not because you are asking a question, but mostly because of the debate it sparks. First off, I think 95% of the people on this forum (well, the ones who actually know what they are talking about), will say they do not need UV lighting. I use them on my tanks, but that is because I have live plants, not for the leos. Mine don't come out enough during the daylight hours to get any of the UV benefits anyway. Most books will tell you the same, because of the fact that they are nocturnal animals, UV isn't needed. I also think most would tell you that a basking light isn't needed either, just a UTH. Anyway, just my 2 cents. Secondly, as for the sand and impaction... I have tried many sands, and to this day I use Reptilite by Carib Sea, and there are those folks on here that will say we are crazy for using sand as a substrate, however, I will say, there is not a single sand substance that I know of that can guarentee 100% against impaction, not a single one, and I work in the pet industry. I can tell you to stay away from Glow in the Dark and colored sands. The GITD contains high amounts of phosphrous which is bad for the lizards, and the colored sands will dye your leos.
That said, you may want to consider these solutions to your leo not eating. Perhaps the room temperature (or more specifically the tanks belly temperature) has dropped enough to cause the leo to "hibernate", during which they won't eat as much, or that perhaps they are reaching maturity during which they will also slow their eating.... Either way, I wouldn't worry about it just yet. Hope some of this helps..
Jeff