Struggling to keep snails alive?  - These are your guys. 
Need food for puffer fish? 

They can live in pretty much anything, freshwater, brackish water, cool water, tropical water. They are are excellent sand sifters, aerating your substrate.  They are livebearers - so no eggs around the tank. They also are not picky eaters, algae, detritus, and extra fish food is all on the menu for them! 

Their numbers can be kept in check by simply not over-feeding your fish!

There will be upwards of 100 snails, anywhere from babies to 1" - with most being roughly 1/4" in size.