I'm not sure what you mean about a "sand trap", but I think what is going on is that the anemone is purposefully crawling under the rock. You'd think if it needed more light, it'd crawl TOWARD the light. But since these things were at the end of the line when they were passing out brains to all the sea creature, they sometimes don't do that. Instead, they go hide in a corner and sulk to death.
I'll let someone with more knowledge about anemones tell you how much lighting you need, but you're going to most likely need VHO
or T5HO, or a clamp-on metal halide. Power Compacts probably aren't going to get you what you need. And then you'll probably be fighting keeping the temperature stable due to the extra heat from the lights. Anemones in small tanks are are not an easy hobby.