Soil should be flush the longest, at 1–2 weeks.
Coco coir should be flush for a shorter time, around one week or less (watch to make sure your plant doesn’t turn too yellow too fast, because coco does not hold on to as much extra nutrients).
During first 2-3 days aim to reduce run-off EC to 200. You could use product like General Hydroponics “FloraKleen” at 5ml/gallon in plain water and no pH adjustment or just use water and maintain run-off EC less than 200