Best sand sifter for sand bed

[Hairytank]

I picked up a Diamond Watchman Goby (orange and blue markings on white) at Red Coral and it does an excellent job of sifting the sand. It sifts sand non-stop on the 2" of the same sand as you, keeping it very clean. Diamond gobies do not carry the sand as high as the yellow head gobies and others; therefore they don't spread sand all over the live rock and corals.
There are several Nassarius snails in my tank and they bury themselves in the sand and will mix it as well.
I also have a serpent star, but it does not seem to do very much sifting.

My goby is the one that does all the work and is very interesting to watch.