i couldn't let this topic go by without adding my 2.2 cents.
i am a big snail fan, and all my tanks have snails that multiply and are procreating to no end (i am kidding), their population stabilizes depending on the food available.
i now have a tank that is only snails. with 1-2 fish. i dont feed the snails anything etc. have some live plants and shine a whole bunch of light. the snails are happy with the algae and also help to keep it down. basically you can lower the light time if there is more algae than what snails can eat.
so no salts. you can add small pieces of zuchini or lettuce if needed. otherwise algae is good enough.