I live in a small town, with a mini pet store inside the hardware store. they are setting up a couple of saltwater tanks. Rather than testing salinity using a hydrometer, they were told its okay to just throw mollies in and if they live, the waters fine. So, they threw 20 mollies straight from FRESHWATER into these SALTWATER tanks (with unknown salinity). I told them that they were going to kill all the mollies, and that they had to be acclimated. Their "fish expert" said "No, this is fine." By the time i saw this, all but 4 of the mollies had died. these 4 were doing very poorly. I'd assume they are all dead by now. and another batch are going in soon.