HI, I'm Karen, finaly managed to get on the computer!
We have a 30 litre biorb tank. We started with 2 platies (1 male, 1 female),and 2 mollies (1 male, 1 female). Couple of weeks later got the 2 male guppies and another female molly. The guppies started chasing the platies within a day or two...