5 gallons is minimum for 1 male and 2 females, or 5 male guppies. But as its tall, i think 1male to 2females is best. But youll have fry.... lots of fry...
yeah i know it sounds bad but im sure that they can be food for other fish untill i am able to get myself some more tanks... but i think a new house must come first (no more space for tanks)