mr. reef says stay away from turbos, they get too big, and in a 10G tank that would be an issue methinks.
I am told one snail/crab per gallon is good, I am slowly adding to my 20G and right now I have 6 various snails/crabs and they are not keeping up. I am going to add another astrea snail some time this week, I think that will keep my glass clean but still need more crabs for the sub strait.