[musho3210]

Welcome to the forum

Whats your room temperature, if the temp is high enough you can go by without a heater

Moss, lots and lots of java moss that covers the bottom and decorations like algae, shrimp would love this

Yes you need a filter, a simple sponge filter would be suffice

A 4 gallon bi-orb costs around 50 american dollars, the jbj 3 gallon picotope is 45 dollars, both comes with a filter and a light.

http://www.jbjnanocubes.com/
you can find the picotope part on the left hand side

http://www.biorb.com/product_details.php?p_id=35&vlang_id=89
thats the biOrb

 

[musho3210]

no need for a heater, plus the biOrb comes with a heater, filters dont take up much space, the picotope filter probably barely interferes. 2-3 gallons is fine for maybe 2 or 3 small shrimp like ghost or cherry, if they breed you can feed the babies to your fish or give the babies to your lfs. Dont do tall hexes, these need more light and dont have as much surface area or ground area. Since shrimp are bottom dwellers the more ground area the better, since they still require oxygen, the more surface area is better.