please remember people, his tank is only 30 litres, about 7.5 gallon. i like to give platies atleast 10 gallon, even more so if they are having fry, i would leave them in the tank, 3platies will soon breed (if you have a female and male) and eventually some fry will survive and stock the tank for you.shrimps might work, or at a push, some pygmy cories on the bottom .but apart from that, i'de say your fully stocked