My nightmare first grow!

Ola amigo tudo bem? Espero que sim. Isso parece muito uma deficiência de potássio. Não deves retirar as folhas, deixa as folhas porque estão boas, não estão totalmente danificadas. Depois de dares uma dose de potássio com ph bem regulado, o problema não vai crescer mais e as folhas aproveitam se. Parabéns pelo cultivo e abraço

Not 100% sure but they could be Springtails( growdiaries.com/grow-questions/39905-white-strange-insects ). The other is like ojeterpelon said mealey bug. If you can see how they react when in a jar of water. If they spring(shoot) really fast across the water around 1" at a time they most likely are. In which case they are harmless to the plant, but usually stress out the grower 😃. As for the look, Your correct in you just flushed them and now they are hungry. When I need to do a flush once I complete the flush I finish it with a light dose of the usual feed to make sure they have something. Good luck and Happy Growing