This is just my opinion, but shrimp will do better in a species only tank. I don't know about Europe, but here is the States you can pick up a 10 gallon tank and heater for about $30. I would use a sponge filter in a species only shrimp tank.

http://www.drsfostersmith.com/produc...2&pcatid=23702

The shrimp will feed off the sponge filter as well.