I've been reading up how to take care of my snail. I am curious, it is mentioned that calcium should be added to the tank once in awhile for a health shell.

How exactly do you safely add calcium to the water? How often for a 16 gallon.

Thanks!

EDIT: I have a single Nerite snail.

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16 gallon- Planted tank, Platies, Pristillia Tetras, assorted Cories, and Golden Aztek Snail
10 gallon- Planted tank, Zebra Danios, Blond Danios, Neon Tetras, Bamboo Shrimp, assorted Cories, and Netrite Snail
2.5 gallon- Planted tank, Velvet tail Betta (Azure), Ghost shrimp, Dwarf African Frog and 1 tiny unknown hitching snail

I used to keep a snail in my 20 gallon aquarium with a small sea shell, looking as if only acting as decoration, but can also be a source of calcium for your snail without changing the water quality. Now the snail lives with my betta fish in a small bowl where I feed him a shrimp pellet every now and again. Since the move, his shell and entire body have been repairing itself from all previous damage. The snail seems to be much happier in a small space with plenty of good food and no predators (unlike my 20 gallon). It's actually funny to watch the betta stalk the snail and give him an occasional bump on the shell.

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"SOUTH AMERICAN BIO-TYPE AQUARIUM" - 20g long tank; 1 south american puffer, 1 dwarf cichlid, 1 clown pleco, 1 black skirt tetra, 1 phantom tetra, 1 serpae tetra, 8 cardinal tetras

10g round tank; 1 orange crayfish, 12+ guppies

1/2g tank; 1 betta

http://www.youtube.com/user/corE3105