I could be mistaken but "deep water turbo snail's" might easily translate into LFS
for "I can charge more money". Honestly though I do not believe there is such a thing but there are several different types of turban spp.
snails. It may just be a different sub.
Many types of snails will "prefer" different types of algaes as well as areas of the tank. Substrate, sand, glass and rock. The best solution IME
, is to get a combination of the ones that touch on all these areas so you are not solely relying on one type for all jobs. If I had the choice though, I would never bother with Astrea snails. You'll spend more time righting them than anything, although they are a great algae grazer. A good mix of cerith, nerite, nassarius and margarita would also be a good choice.