I second <span class="link_user">@smoke24</span> about light stress. Had the same with my HLG fixtures, these new led diodes are mega powerful with minimal heat, the good old rules to determine light heights you find on sites apply to HPS/MH mostly, but not high end LEDs. Try to stick with the manual that comes with the light, however I had to move my HLG a few inches further than listed on their site cuz it slowly burned my babies with too intense light (not heat).
