Ever hear of a "salt rock"? with BONUS PUFFER QUESTION!

A friend of mine just passed on a translucent blue-tinged crystal he
calls a "salt rock," telling me if I put it in my puffer tank it will
slowly release the appropriate amount of salt in the water for them
over time.

It doesn't seem particularly water-soluble, nor does it taste like
salt.

Anyone here know of such a thing?

BONUS PUFFER QUESTION:

I now know, thanks to this NG, that puffers need to eat snails on
occasion to keep their teeth under control. How often should they have
snails to snack on?

SUPER PUFFER BONUS ROUND:

And when I give them trumpet snails, they seem to suck out the
delicious insides without eating the tough outsides. Sort of like my
approach to a stale jelly donut. Is this adequate for the
tooth-cutting needs, or do I need to find more edible snails?

Thanks,


- Matt
www.man-man.org