Planted tanks and natural sunlight

[Mr.Fish]

Not sure about some of the shrimp species appropriate for colder water, but there are other crustaceans, such as crayfish that would live in an unheated tank. In fact, they are accustomed to living in 4 seasons.

Consider what you will be feeding the shrimp/crusty...you may have an issue with excessive clouding of the water if you have no filter mechanisms. It may be a delicate balance between feeding crusty and overfeeding w/ no filtration. Just IMHO

 

[RTR]

Ms. Waldstad actually pushes feeding heavily. But you cannot pick and chose from her techniques, you got the whole route or do not play.

Arklady - see also: http://naturalaquariums.com/
if you have not found that site yet.

 

[TKOS]

If you could find a crayfish species that stays small it would work. I don't know about crabs, but they tend to be a lot of bother with their constant escaping and all. The only shrimp I have had lived in a heated tank so I don't know that.

But there are lots of varieties of snails. I feed mine once a week or so, just some fish flakes added in. Occasionally I give them a slice of raw broccolli. They love it and I leave it there til it is completely eaten.

 

[RTR]

But crayfish are no-nos in planted tanks - they are animate chainsaws.