hi to every one please could you help me with a little prob ive kept tropical fish 4 over a year now my daughter has kept a small aqua start 320 tank for 6 months now and ive just got her a 54 litre juwel tank how many community fish can i put in it with out over crowding it i know to put fish in the tank in 2 months time just not sure on how many i have about 20 in my 3ft tank but with this been my daughters tank i was wanting to put in as many as i can but i really dont want to over crowd the tank can any one please help