I seem to be unable to keep turbos alive. I bought a couple as part of my clean-up crew and they lasted a few weeks before I found one upside down. Thinking it was just stupid, I tipped it up the right way but it never moved again (so I assume it is dead). A week or two later, 2nd one went the same way. I bought two more and one of those did the same thing. I bought another. within a month I found it (or it's friend) in the same condition. Water is fine (hermits and brittle star are fine). LR is thriving.
I've had the tank several months now and am just considering adding something "pretty" to it (not sure what yet) but dont want to do anything if I cannot even keep a snail alive.
In case it helps ... Orca 450L nano. One green brittle. One red-legged hermit. One blue-legged hermit. One (now) turbo. A lot of what might be macro-algae. Feed once a day with crab pellets (I expect I should vary the diet some but the crabs run for the pellets and the star likes them too).
I did consider that and cannot prove it isn't but since the brittle leaves the crabs alone and I've never seen it attack a snail I assumed not. I also assumed it would find it hard to get to the snails (what with the shell and all).
How are you acclimating the snails? Snails are among the most sensitive things you can put in your tank in regards to salinity. If you have a major dif between your tank and the LFS's tank salinity, then you need several hours to acclimate a snail. I made the mistake of listening to one LFS "oh, you can just chuck these in without acclimatizing them first". One died instantly, 2 more died within 3 days, 2 more by the second week, and now all the snails i bought from there are dead. Turns out, the water was 1.031 and my tank was 1.023.
Snails have a complex circulatory system and sudden changes in salinity can cause their kidneys to explode killing them within minutes to days.