Can snails live in a hyposalinity enviroment?

I got a fish (magnificent rabbit) with ICH so I have been treating it in a
120gal tank I had setup but did not have anything in it but 3 emerald crabs
and a buncha snails for cleanup. I was useing Ruby Reef's Kick ICH along
with lowering the salinity to 1.010 and raising the temp to 80-81 degrees.
Well the higher temp killed all my snails which I figured might happen. So
the ICH seems to be comeing under control but I know I need to wait quite
some time to be sure. I have lowed the temp back to around 78 degrees. I am
starting to have a green algae problem since my snails are all dead. So
yesterday I bought some snails from the LFS. I knew my salinity was alot
lower than where they were coming from so I took extra care and longer
adjustment period before dropping them in the tank. Well they ALL died. I
was told by the LFS the lower salinity should not effect them but I am
wondering if that is true. All other tests are fine (ph,nitrate,etc). So my
question is :
Can snails live a tank with such a low salinity?

thanks!
G.