When I first got mine they were between 1/2" for the smallest, and 1" for the largest
after a year, the females were around 4.5"-5" and the largest male about 7"
He's a little larger now, I feed a low protein variety of pellets no more than once per day (and I like to skip a day once or twice per week), and try to do a 30% water change every other day.