To better answer your question I will need a little more detail. What I think you might be asking is if its better to grow under LED and then trasition to an HID? This is very typical of growers who just want to get their feet wet in the LED market while lowering their overall energy consumption. Going to an HID light for flowering is not necessary anymore with the qualtiy of LED grow lights that are in the market today. Yop will also notice stress occurs when switching from LED to HID. This can be very minimal if the HID lights are turn down to the lowest setting and very far away from the plant canopy for a couple days.