I went to my LFS today. I have a bunch of snails showing up tomorrow but I wanted to add a sand sifting star. I asked if they had any and the guy told me they stopped selling them because they found out they do their job so well that in about 2-3 years you are left with a dead sand bed, devoid of all the beneficial bacteria and stuff that makes it "live" sand. He said nassarius snails are the best.\n\nSo needless to say I left empty handed.\nAnyone else know this? This was news to me.