I am with plum70rt on this one. I have a sand star in my 29g, and my pods and worms have been thriving. I also have a leopard wrasse that eats pods too, and the population is doing very well.
I also did NOT have worms when I got the star, but now I do...so they have been thriving as well.
I have more pods (copepods and amphipods alike) now than before the star.
I was skeptical at first in getting the star, because I heard from everyone that they will deplete your sandbed. I am just not finding that to be true in my case.