Insecticidal soap with added neem or canola oil at 10ml/L Hit well every 4 days for 4 treatments. Make sure to spray the top of the soil a bit too as the f'ers jump around.
Use some yellow sticky pads to catch any adult thrips flying around. Use a bio insecticidal of some sort to get rid of them faster and more effectively than neem oil and like OldMedUser says, spray the top soil a bit too for sure.