Hi i just purchased a couple of severums .... one is plain cream in colour and the other is cream/yellow with spots . how do i tell male from a female? oh and how quick are they going to grow? i also have 3 angels a pleco ,1 gorami,2 danos ...... all are young .... what sizes am i looking at? and what size tank in cm or mils am i going to need ? can i have any advice that could make my life easyer.... as i have now herd severums are nasty