Clownfish fry hatching at different times

[Reef Puffer]

Mine do this. Like day 9 and10. I pulled the whole shell with the eggs when I first tried. The next day there was still 30% of the eggs unhatched. I returned them to the mother tank, I think it helped the parents not get too stressed. I can't tell you how siphoning well affect them? Mine lay eggs every couple weeks and have been for like 8 months now. They don't all always hatch the same night.