i have to disagree with you in part Bill. yes, if you're water is bad, or you have too little flow, you'll have trouble, but the presence of "sand sifters" does nothing to alleviate the diatom bloom. infact, it may lengthen the time of the bloom due to disturbing it.
the only "sand sifters" i run are a few Nassarius snails and some Ceriths, but i don't stock them because they sleep in the substrate. I stock them for their niches in my CUC. in fact, unless you have a whole booty-load of them, the amount of substrate they sift is minimal IME.
as for sand sifter stars, they require a lot of open substrate to thrive/survive, and even then will deplete the substrate of beneficial microfauna, which isn't such a great thing, IMHO.
if one really wants a critter to turn the substrate over, a sleeper/watchman goby is about as good as you can get, but even then, they're filtering out the microfauna from the substrate.
nothing is free...one has to decide what's important to them and their setup.
Amy,
i'd order some XL Nassarius, Trochus and/or zebra turbo/Trochus. if they can get Nerites and Ceriths, i'd go for those as well. that would give you a good mix. for now, i'd go with 1 snail/2-3 gals stocking density, except the Nassarius (go 1/10gals max). grab a few peppermint shrimp as well (for now, go 1/25 gals, but isuspect you'll want to bump that up as you get a feel for the tank, but only go 1/10 gals max). i'd leave the stars, personally...