By continuing to use the website or clicking Accept you consent to our cookies and personal data policy and confirm that you are at least 18 year old. For details please see Privacy Policy and Terms
m0use has the best advice here... it's all going to depend on what stage your plants are in and the manual will be your best source for an answer.
Good luck!
As mouse stated the grow manual or simply go to the website for that specific model light. Hope that helps. SF does a good light, I have been happy with mine. Enjoy the grow.