Hi folks, new user here. I have an orange platy that has just given birth in a nursery box. She had 20 babies. I don't see any more coming, but I am wondering how I will know for sure that she has given birth to all the babies inside her. As soon as she's done, I would like to take her out of the nursery! Also, how big do the babies need to be before I swish the box up and down to clean the gunk out that has collected at the bottom? Thanks!