Happy to answer Rossano, who like many has come to the first "breakthrough" with aquariums, time to move to a larger pool, after the first aquarium. :-)

Selling a used tank is not easy ... if hardly anyone wants to send around Italy, with the cost of delivery and the risks ... but a 80x40x50, such as the aquarium of Rossano, is not large, so as first aquarium is great for anyone, in fact better than trying to place a bigger one. At least that ...
In Rome with Portaportese is easy, try out EBAY, or Kijiji, and especially in industry forums. Even here on Acquariando anyone can write and his small space it can have, for sale to aquariums and accessories.

This is why many places on the terrace or in the garden their first aquarium , maybe turning it into a small cage, or holding each plants and small fish in our lakes and rivers (warm water) or a herd of live food, such as easy Daphnia, the Artemia have not and you can also try the Guppy, if we take large cichlids such as South American or African.