Hi mate, not sure about the dimmer for the Lumatek but as a rule you start your seeds/seedlings on the lowest setting. 50% max for veg as veg doesn't need really intense light. For flowering i would gradually raise it from 50%. Getting to 100% by week 4 of flower. You can judge for yourself if she needs more or less light during your grow but those levels should set you up right. Good luck and happy growing