The tiny Turbos are probably Collonista snails, or some of their tiny relatives. They often reproduce in reef tanks. As for the ones that look like Nassarius, they could be one of a couple of small Nassarius species, or something else entirely. But, rather than reproducing, it's more likely that they came into your tank as tiny juveniles, and are just now large enough that you are seeing them. Most of them have pelagic reproductive stages that make aquarium breeding very unlikely.
Cheers,
Don