I hav efound taht Cerith Snails and Sand sifting stars are the best bet. Cerith snails chow the algea on the sand and will burrow in the sandbed feedign on algea. as a bonus they reproduce redaily in aquaria, so you could start a little family. A month ago, mine were laying eggs every other day or so, but several days after the eggs disappeared. I figured that my fish were eating them, but i check my tank at nigt a couple days ago and there were like 10 tiny snails cruising around the sandbed! They are kinda hard to get ahold of at lfs's but are readily available on the net! i dont know if swfish.com has them or not though!
good luck
jon